Prospectus				Filed pursuant to Rule 424(b)(3) File No. 333-146953

21,555,215 shares of common stock

     This prospectus relates to the offering by the selling stockholders of Gran Tierra Energy Inc. of up to 21,555,215 shares of our common stock, par value $0.001 per share. These shares of common stock consist of shares of common stock issued to, or issuable to, the selling stockholders upon exchange of exchangeable shares of Gran Tierra Goldstrike, Inc., an indirect subsidiary of Gran Tierra Energy Inc. previously held or currently held by the selling stockholders. The exchangeable shares were issued to the selling stockholders in a private offering in November 2005. Also includes 2,825,059 shares issuable upon exercise of warrants held by three selling stockholders issued in connection with a private placement in June 2006.

     We will not receive any proceeds from the sale of common stock by the selling stockholders. We may receive proceeds from the exercise price of the warrants if they are exercised by the selling stockholders. We intend to use any proceeds received from the selling stockholders’ exercise of the warrants for working capital and general corporate purposes.

     The selling stockholders have advised us that they will sell the shares of common stock from time to time in the open market, on the OTC Bulletin Board, in privately negotiated transactions or a combination of these methods, at market prices prevailing at the time of sale, at prices related to the prevailing market prices, at negotiated prices, or otherwise as described under the section of this prospectus titled “Plan of Distribution.”

     Our common stock is traded on the OTC Bulletin Board under the symbol “GTRE.OB”. On December 19, 2007, the closing price of the common stock was $2.13 per share.

     Investing in our common stock involves risks. Before making any investment in our securities, you should read and carefully consider risks described in the Risk Factors beginning on page 4 of this prospectus.

     You should rely only on the information contained in this prospectus or any prospectus supplement or amendment. We have not authorized anyone to provide you with different information.

     Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus is dated December 20, 2007

     You should rely only on the information contained in this prospectus and any free-writing prospectus that we authorize to be distributed to you. We have not authorized anyone to provide you with information different from or in addition to that contained in this prospectus or any related free-writing prospectus. If anyone provides you with different or inconsistent information, you should not rely on it. The selling stockholders are offering to sell, and are seeking offers to buy, shares of common stock only in jurisdictions where offers and sales are permitted. The information contained in this prospectus is accurate only as of the date of this prospectus, regardless of the time of delivery of this prospectus or of any sale of the common stock. Our business, financial conditions, results of operations and prospects may have changed since that date.

     For investors outside of the United States: We have not done anything that would permit this offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. You are required to inform yourselves about and to observe any restrictions relating to this offering and the distribution of this prospectus.

TABLE OF CONTENTS

		Page
Summary			2
Risk Factors			4
Special Note Regarding Forward-Looking Statements			17
Dividend Policy			17
Use Of Proceeds			17
Price Range Of Common Stock			17
Selected Financial Data			19
Management’s Discussion And Analysis Of Financial Condition And Results Of Operations			20
Business			36
Management			57
Principal And Selling Stockholders			69
Certain Relationships And Related Transactions			77
Description Of Capital Stock			79
Plan Of Distribution			82
Legal Matters			85
Experts			85
Where You Can Find Additional Information			86
Index to Consolidated Financial Statements			F-1

SUMMARY

     This summary highlights information contained elsewhere in this prospectus but might not contain all of the information that is important to you. Before investing in our common stock, you should read the entire prospectus carefully, including the “Risk Factors” section and our financial statements and the notes thereto included elsewhere in this prospectus.

     For purposes of this prospectus, unless otherwise indicated or the context otherwise requires, all references herein to “Gran Tierra,” “we,” “us,” and “our,” refer to Gran Tierra Energy Inc., a Nevada corporation, and our subsidiaries.

Our Company

     On November 10, 2005, Goldstrike, Inc. (“Goldstrike”), Gran Tierra Energy Inc., a privately-held Alberta corporation which we refer to as “Gran Tierra Canada” and the holders of Gran Tierra Canada’s capital stock entered into a share purchase agreement, and Goldstrike and Gran Tierra Goldstrike Inc. (which we refer to as Goldstrike Exchange Co.) entered into an assignment agreement. In these two transactions, the holders of Gran Tierra Canada’s capital stock acquired shares of either Goldstrike common stock or exchangeable shares of Goldstrike Exchange Co., and Goldstrike Exchange Co. acquired substantially all of Gran Tierra Canada’s capital stock. Immediately following the transactions, Goldstrike Exchange Co. acquired the remaining shares of Gran Tierra Canada outstanding after the initial share exchange for shares of common stock of Gran Tierra Energy Inc. using the same exchange ratio as used in the initial exchange. This two step process was part of a single transaction whereby Gran Tierra Canada became a wholly-owned subsidiary of Goldstrike Inc. Additionally, Goldstrike changed its name to Gran Tierra Energy Inc. with the management and business operations of Gran Tierra Canada, but remains incorporated in the State of Nevada.

     Following the above-described transaction, our operations and management are substantially the operations and management of Gran Tierra Canada prior to the transactions. The former Gran Tierra Canada was formed by an experienced management team in early 2005, with extensive hands-on experience in oil and natural gas exploration and production in most of the world’s principal petroleum producing regions. Our objective is to acquire and exploit international opportunities in oil and natural gas exploration, development and production, focusing on South America. We made our initial acquisition of oil and gas producing and non-producing properties in Argentina in September 2005. In addition, we recently acquired assets in Colombia and other minor interests in Argentina and Peru.

Recent Developments

     In September 2007, we announced that we had revised our revised initial estimates of reserves as a result of two recent oil discoveries in Colombia. For our Costayaco oil discovery, we now estimate proved reserves of 2.7 million barrels of oil. The discovery of the Costayaco field in the Chaza Block, located in the Putumayo Basin of Colombia and operated by us, was the result of drilling the Costayaco-1 exploration well in the second quarter of 2007. This well tested 5,906 barrels of oil per day, gross before royalties.

     For our Juanambu discovery, we now estimate proved reserves of 0.1 million barrels of oil. The discovery of the Juanambu field in the Guayuyaco Block, also located in the Putumayo Basin of Colombia and operated by us, was the result of drilling the Juanambu-1 exploration well early in 2007. This well tested 778 barrels of oil per day, gross before royalties.

     As a result of the adjustments and production for the first half of 2007, our estimate of proved reserves, net of royalties, as of June 30, 2007, stands at 5.6 million barrels of oil. This contrasts to our December 31, 2006 estimate of proved reserves of 3.0 million barrels of oil.

     For the third quarter of 2007, the company reported oil and condensate production of 1,526 barrels per day, net after royalty, as compared to 1,043 for the same quarter of 2006. For the nine month period ended September 30, 2007 the company reported oil and condensate production of 1,270 barrels per day, net after royalty, as compared to 570 barrels per day for the comparable period of 2006.

Corporate Information

     Goldstrike Inc., now known as Gran Tierra Energy Inc., was incorporated under the laws of the State of Nevada on June 6, 2003. Our principal executive offices are located at 300, 611 - 10^th Avenue S.W., Calgary, Alberta, Canada. The telephone number at our principal executive offices is (403) 265-3221. Our website address is www.grantierra.com. Information contained on our website is not deemed part of this prospectus.

The Offering

Common stock currently outstanding (1)				95,051,909 shares
Common stock offered by the selling stockholders (2)				21,555,215 shares
Common stock outstanding after the offering (3)				97,876,968 shares
Use of Proceeds				We will not receive any proceeds from the sale of common stock offered by this prospectus. We will receive the proceeds from any warrant exercises, which we intend to use for general corporate purposes, including for working capital.
OTC Bulletin Board Symbol				GTRE.OB

RISK FACTORS

     Investing in our common stock involves a high degree of risk. You should carefully consider the risks below before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. In such case, the trading price of our common stock could decline and you could lose all or part of your investment.

Risks Related to Our Business

     We are a new enterprise engaged in the business of oil and natural gas exploration and development. The business of exploring for, developing and producing oil and natural gas reserves is inherently risky. We will face numerous and varied risks which may prevent us from achieving our goals.

We are a Company With Limited Operating History for You to Evaluate Our Business. We May Never Attain Profitability.

     We have limited current oil or natural gas operations. As an oil and gas exploration and development company with limited operating history, it is difficult for potential investors to evaluate our business. Our proposed operations are therefore subject to all of the risks inherent in light of the expenses, difficulties, complications and delays frequently encountered in connection with the formation of any new business, as well as those risks that are specific to the oil and gas industry. Investors should evaluate us in light of the delays, expenses, problems and uncertainties frequently encountered by companies developing markets for new products, services and technologies. We may never overcome these obstacles. Our accumulated deficit as of September 30, 2007 is $18,673,955.

     Our business is speculative and dependent upon the implementation of our business plan and our ability to enter into agreements with third parties for the rights to exploit potential oil and gas reserves on terms that will be commercially viable for us.

Unanticipated Problems in Our Operations May Harm Our Business and Our Viability.

     If our operations in South America are disrupted and/or the economic integrity of these projects is threatened for unexpected reasons, our business may experience a setback. These unexpected events may be due to technical difficulties, operational difficulties which impact the production, transport or sale of our products, geographic and weather conditions, business reasons or otherwise. Because we are at the beginning stages of our development, we are particularly vulnerable to these events. Prolonged problems may threaten the commercial viability of our operations. Moreover, the occurrence of significant unforeseen conditions or events in connection with our acquisition of operations in South America may cause us to question the thoroughness of our due diligence and planning process which occurred before the acquisitions, which may cause us to reevaluate our business model and the viability of our contemplated business. Such actions and analysis may cause us to delay development efforts and to miss out on opportunities to expand our operations.

We May Be Unable to Obtain Development Rights We Need to Build Our Business, and Our Financial Condition and Results of Operations May Deteriorate.

     Our business plan focuses on international exploration and production opportunities, initially in South America and later in other parts of the world. Thus far, we have acquired interests for exploration and development in eight properties in Argentina, eight properties in Colombia and two properties in Peru. In the event that we do not succeed in negotiating additional property acquisitions, our future prospects will likely be substantially limited, and our financial condition and results of operations may deteriorate.

Our Lack of Diversification Will Increase the Risk of an Investment in Our Common Stock.

     Our business will focus on the oil and gas industry in a limited number of properties, initially in Argentina, Colombia and Peru, with the intention of expanding elsewhere in South America and later into other parts of the world. Larger companies have the ability to manage their risk by diversification. However, we will lack diversification, in terms of both the nature and geographic scope of our business. As a result, factors affecting our industry or the regions in which we operate will likely impact us more acutely than if our business were more diversified.

Strategic Relationships Upon Which We May Rely are Subject to Change, Which May Diminish Our Ability to Conduct Our Operations.

     Our ability to successfully bid on and acquire additional properties, to discover reserves, to participate in drilling opportunities and to identify and enter into commercial arrangements will depend on developing and maintaining effective working relationships with industry participants and on our ability to select and evaluate suitable properties and to consummate transactions in a highly competitive environment. These realities are subject to change and may impair Gran Tierra’s ability to grow.

     To develop our business, we will endeavor to use the business relationships of our management to enter into strategic relationships, which may take the form of joint ventures with other private parties or with local government bodies, or contractual arrangements with other oil and gas companies, including those that supply equipment and other resources that we will use in our business. We may not be able to establish these strategic relationships, or if established, we may not be able to maintain them. In addition, the dynamics of our relationships with strategic partners may require us to incur expenses or undertake activities we would not otherwise be inclined to in order to fulfill our obligations to these partners or maintain our relationships. If our strategic relationships are not established or maintained, our business prospects may be limited, which could diminish our ability to conduct our operations.

Competition in Obtaining Rights to Explore and Develop Oil and Gas Reserves and to Market Our Production May Impair Our Business.

     The oil and gas industry is highly competitive. Other oil and gas companies will compete with us by bidding for exploration and production licenses and other properties and services we will need to operate our business in the countries in which we expect to operate. This competition is increasingly intense as prices of oil and natural gas on the commodities markets have risen in recent years. Additionally, other companies engaged in our line of business may compete with us from time to time in obtaining capital from investors. Competitors include larger, foreign owned companies, which, in particular, may have access to greater resources than us, may be more successful in the recruitment and retention of qualified employees and may conduct their own refining and petroleum marketing operations, which may give them a competitive advantage. In addition, actual or potential competitors may be strengthened through the acquisition of additional assets and interests.

We May Be Unable to Obtain Additional Capital that We Will Require to Implement Our Business Plan, Which Could Restrict Our Ability to Grow.

     We expect that our cash balances and cash flow from operations will be sufficient only to provide a limited amount of working capital, and the revenues generated from our properties in Argentina and Colombia will not alone be sufficient to fund our operations or planned growth. We will require additional capital to continue to operate our business beyond the initial phase of our current activities and to expand our exploration and development programs to additional properties. We may be unable to obtain additional capital required. Furthermore, inability to obtain capital may damage our reputation and credibility with industry participants in the event we cannot close previously announced transactions.

     Future acquisitions and future exploration, development and production activities, as well as our general overhead expenses (including salaries, travel, office, consulting, audit and legal costs) will require a substantial amount of additional capital and cash flow.

     When we require additional capital we plan to pursue sources of such capital through various financing transactions or arrangements, including joint venturing of projects, debt financing, equity financing or other means. We may not be successful in locating suitable financing transactions in the time period required or at all, and we may not obtain the capital we require by other means. If we do succeed in raising additional capital, the capital received through our past private offerings to accredited investors may not be sufficient to fund our operations going forward without obtaining additional capital financing. Furthermore, future financings are likely to be dilutive to our stockholders, as we will most likely issue additional shares of common stock or other equity to investors in future financing transactions. In addition, debt and other mezzanine financing may involve a pledge of assets and may be senior to interests of equity holders. We may incur substantial costs in pursuing future capital financing, including investment banking fees, legal fees, accounting fees, securities law compliance fees, printing and distribution expenses and other costs. We may also be required to recognize non-cash expenses in connection with certain securities we may issue, such as convertibles and warrants, which will adversely impact our financial condition.

     Our ability to obtain needed financing may be impaired by such factors as the capital markets (both generally and in the oil and gas industry in particular), our status as a new enterprise with a limited history, the location of our oil and natural gas properties in South America and prices of oil and natural gas on the commodities markets (which will impact the amount of asset-based financing available to us) and/or the loss of key management. Further, if oil and/or natural gas prices on the commodities markets decrease, then our revenues will likely decrease, and such decreased revenues may increase our requirements for capital. Some of the contractual arrangements governing our exploration activity may require us to commit to certain capital expenditures, and we may lose our contract rights if we do not have the required capital to fulfill these commitments. If the amount of capital we are able to raise from financing activities, together with our revenues from operations, is not sufficient to satisfy our capital needs (even to the extent that we reduce our operations), we may be required to cease our operations.

If We Fail to Make the Cash Calls Required by Our Current Joint Ventures or Any Future Joint Ventures, We May be Required to Forfeit Our Interests in Such Joint Ventures and Our Results of Operations and Our Liquidity Would be Negatively Affected.

     If we fail to make the cash calls required by our joint ventures, we may be required to forfeit our interests in such joint ventures, which could substantially affect the implementation of our business strategy. We were required to place $400,000 in escrow to secure future cash calls in conjunction with the acquisition of our interest at Palmar Largo in Argentina, which funds have now been returned to us. However, in the future we will be required to make periodic cash calls in connection with our Palmar Largo joint venture and other joint ventures where we are not the operator, or we may be required to place additional funds in escrow to secure our obligations related to our joint venture activity. If we fail to make the cash calls required in connection with the joint ventures, whether because of our cash constraints or otherwise, we will be subject to certain penalties and eventually would be required to forfeit our interest in the joint venture.

We May Not Be Able To Effectively Manage Our Growth, Which May Harm Our Profitability.

     Our strategy envisions expanding our business. If we fail to effectively manage our growth, our financial results could be adversely affected. Growth may place a strain on our management systems and resources. We must continue to refine and expand our business development capabilities, our systems and processes and our access to financing sources. As we grow, we must continue to hire, train, supervise and manage new employees. We may not be able to:

	•		expand our systems effectively or efficiently or in a timely manner;
	•		allocate our human resources optimally;
	•		identify and hire qualified employees or retain valued employees; or
	•		incorporate effectively the components of any business that we may acquire in our effort to achieve growth.

     If we are unable to manage our growth and our operations our financial results could be adversely affected by inefficiency, which could diminish our profitability.

Our Business May Suffer If We Do Not Attract and Retain Talented Personnel.

     Our success will depend in large measure on the abilities, expertise, judgment, discretion integrity and good faith of our management and other personnel in conducting the business of Gran Tierra. We have a small management team consisting of Dana Coffield, our President and Chief Executive Officer, Martin Eden, our Vice President, Finance and Chief Financial Officer, Max Wei, our Vice President, Operations, Rafael Orunesu, our

President of Gran Tierra activities in Argentina, and Edgar Dyes, our President of Gran Tierra activities in Colombia. The loss of any of these individuals or our inability to attract suitably qualified staff could materially adversely impact our business. We may also experience difficulties in certain jurisdictions in our efforts to obtain suitably qualified staff and retaining staff who are willing to work in that jurisdiction. We do not currently carry life insurance for our key employees.

     Our success depends on the ability of our management and employees to interpret market and geological data successfully and to interpret and respond to economic, market and other business conditions in order to locate and adopt appropriate investment opportunities, monitor such investments and ultimately, if required, successfully divest such investments. Further, our key personnel may not continue their association or employment with Gran Tierra and we may not be able to find replacement personnel with comparable skills. We have sought to and will continue to ensure that management and any key employees are appropriately compensated; however, their services cannot be guaranteed. If we are unable to attract and retain key personnel, our business may be adversely affected.

We may not be Able to Continue as a Going Concern.

     Our consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. We have a history of net losses that may continue in the future. We have included an explanatory paragraph in Note 1 of our audited financial statements for the year ended December 31, 2006, and unaudited financial statements for the period ended September 30, 2007, to the effect that our dependence on equity and debt financing raises substantial doubt about our ability to continue as a going concern. Our accumulated deficit at September 30, 2007 was $18.7 million. Our financial statements do not include any adjustments that might be necessary should we be unable to continue as a going concern.

     Our operations must begin to provide sufficient revenues to improve our working capital position. If we are unable to become profitable and cannot generate cash flow from our operating activities sufficient to satisfy our current obligations and meet our capital investment objectives, we may be required to raise additional capital or debt to fund our operations, reduce the scope of our operations or discontinue our operations.

Risks Related to our Prior Business May Adversely Affect our Business.

     Before the share exchange transaction between Goldstrike and Gran Tierra Canada, Goldstrike’s business involved mineral exploration, with a view towards development and production of mineral assets, including ownership of 32 mineral claim units in a property in British Columbia, Canada and the exploration of this property. We have determined not to pursue this line of business following the share exchange, but could still be subject to claims arising from the former Goldstrike business. These claims may arise from Goldstrike’s operating activities (such as employee and labor matters), financing and credit arrangements or other commercial transactions. While no claims are pending and we have no actual knowledge of any threatened claims, it is possible that third parties may seek to make claims against us based on Goldstrike’s former business operations. Even if such asserted claims were without merit and we were ultimately found to have no liability for such claims, the defense costs and the distraction of management’s attention may harm the growth and profitability of our business. While the relevant definitive agreements executed in connection with the share exchange provide indemnities to us for liabilities arising from the prior business activities of Goldstrike, these indemnities may not be sufficient to fully protect us from all costs and expenses.

Maintaining and improving our financial controls may strain our resources and divert management’s attention, and if we are not able to report that we have effective internal controls our stock price may suffer.

     We are subject to the requirements of the Securities Exchange Act of 1934, or the Exchange Act, including the requirements of the Sarbanes-Oxley Act of 2002. The requirements of these rules and regulations have increased, and we expect will continue to increase, our legal and financial compliance costs, make some activities more difficult, time-consuming or costly and may also place undue strain on our personnel, systems and resources. The Sarbanes-Oxley Act requires, among other things, that we maintain effective disclosure controls and procedures and internal control over financial reporting. This can be difficult to do. As a result of this and similar activities, management’s attention may be diverted from other business concerns, which could have a material adverse effect on our business, financial condition and results of operations. In addition, if we are unable to report in our Annual Report on Form 10-K for 2007 that we maintain effective internal control over financial reporting, investor confidence in our management may decrease, which could have an adverse effect on our stock price.

Risks Related to Our Industry

Our Exploration for Oil and Natural Gas Is Risky and May Not Be Commercially Successful, Impairing Our Ability to Generate Revenues from Our Operations.

     Oil and natural gas exploration involves a high degree of risk. These risks are more acute in the early stages of exploration. Our expenditures on exploration may not result in new discoveries of oil or natural gas in commercially viable quantities. It is difficult to project the costs of implementing an exploratory drilling program due to the inherent uncertainties of drilling in unknown formations, the costs associated with encountering various drilling conditions, such as over pressured zones and tools lost in the hole, and changes in drilling plans and locations as a result of prior exploratory wells or additional seismic data and interpretations thereof. If exploration costs exceed our estimates, or if our exploration efforts do not produce results which meet our expectations, our exploration efforts may not be commercially successful, which could adversely impact our ability to generate revenues from our operations.

We May Not Be Able to Develop Oil and Gas Reserves on an Economically Viable Basis, and Our Reserves and Production May Decline as a Result.

     To the extent that we succeed in discovering oil and/or natural gas reserves may not be capable of production levels we project or in sufficient quantities to be commercially viable. On a long-term basis, our company’s viability depends on our ability to find or acquire, develop and commercially produce additional oil and gas reserves. Without the addition of reserves through exploration, acquisition or development activities, our reserves and production will decline over time as reserves are produced. Our future reserves will depend not only on our ability to develop then-existing properties, but also on our ability to identify and acquire additional suitable producing properties or prospects, to find markets for the oil and natural gas we develop and to effectively distribute our production into our markets.

     Future oil and gas exploration may involve unprofitable efforts, not only from dry wells, but from wells that are productive but do not produce sufficient net revenues to return a profit after drilling, operating and other costs. Completion of a well does not assure a profit on the investment or recovery of drilling, completion and operating costs. In addition, drilling hazards or environmental damage could greatly increase the cost of operations, and various field operating conditions may adversely affect the production from successful wells. These conditions include delays in obtaining governmental approvals or consents, shut-downs of connected wells resulting from extreme weather conditions, problems in storage and distribution and adverse geological and mechanical conditions. While we will endeavor to effectively manage these conditions, we cannot be assured of doing so optimally, and we will not be able to eliminate them completely in any case. Therefore, these conditions could diminish our revenue and cash flow levels and result in the impairment of our oil and natural gas interests.

Estimates of Oil and Natural Gas Reserves that We Make May Be Inaccurate and Our Actual Revenues May Be Lower than Our Financial Projections.

     We will make estimates of oil and natural gas reserves, upon which we will base our financial projections. We will make these reserve estimates using various assumptions, including assumptions as to oil and natural gas prices, drilling and operating expenses, capital expenditures, taxes and availability of funds. Some of these assumptions are inherently subjective, and the accuracy of our reserve estimates relies in part on the ability of our management team, engineers and other advisors to make accurate assumptions. Economic factors beyond our control, such as interest rates and exchange rates, will also impact the value of our reserves. The process of estimating oil and gas reserves is complex, and will require us to use significant decisions and assumptions in the evaluation of available geological, geophysical, engineering and economic data for each property. As a result, our reserve estimates will be inherently imprecise. Actual future production, oil and natural gas prices, revenues, taxes, development expenditures, operating expenses and quantities of recoverable oil and gas reserves may vary substantially from those we estimate. If actual production results vary substantially from our reserve estimates, this could materially reduce our revenues and result in the impairment of our oil and natural gas interests.

Drilling New Wells Could Result in New Liabilities, Which Could Endanger Our Interests in Our Properties and Assets.

     There are risks associated with the drilling of oil and natural gas wells, including encountering unexpected formations or pressures, premature declines of reservoirs, blow-outs, craterings, sour gas releases, fires and spills. The occurrence of any of these events could significantly reduce our revenues or cause substantial losses, impairing our future operating results. We may become subject to liability for pollution, blow-outs or other hazards. We will obtain insurance with respect to these hazards, but such insurance has limitations on liability that may not be sufficient to cover the full extent of such liabilities. The payment of such liabilities could reduce the funds available to us or could, in an extreme case, result in a total loss of our properties and assets. Moreover, we may not be able to maintain adequate insurance in the future at rates that are considered reasonable. Oil and natural gas production operations are also subject to all the risks typically associated with such operations, including premature decline of reservoirs and the invasion of water into producing formations.

Decommissioning Costs Are Unknown and May be Substantial; Unplanned Costs Could Divert Resources from Other Projects.

     We may become responsible for costs associated with abandoning and reclaiming wells, facilities and pipelines which we use for production of oil and gas reserves. Abandonment and reclamation of these facilities and the costs associated therewith is often referred to as “decommissioning.” We have determined that we do not require a significant reserve account for these potential costs in respect of any of our current properties or facilities at this time but if decommissioning is required before economic depletion of our properties or if our estimates of the costs of decommissioning exceed the value of the reserves remaining at any particular time to cover such decommissioning costs, we may have to draw on funds from other sources to satisfy such costs. The use of other funds to satisfy such decommissioning costs could impair our ability to focus capital investment in other areas of our business.

Our Inability to Obtain Necessary Facilities Could Hamper Our Operations.

     Oil and natural gas exploration and development activities are dependent on the availability of drilling and related equipment, transportation, power and technical support in the particular areas where these activities will be conducted, and our access to these facilities may be limited. To the extent that we conduct our activities in remote areas, needed facilities may not be proximate to our operations, which will increase our expenses. Demand for such limited equipment and other facilities or access restrictions may affect the availability of such equipment to us and may delay exploration and development activities. The quality and reliability of necessary facilities may also be unpredictable and we may be required to make efforts to standardize our facilities, which may entail unanticipated costs and delays. Shortages and/or the unavailability of necessary equipment or other facilities will impair our activities, either by delaying our activities, increasing our costs or otherwise.

We are not the Operator of All Our Current Joint Ventures and Therefore the Success of the Projects Held Under Joint Ventures is Substantially Dependent On Our Joint Venture Partners.

     As our company does not operate all the joint ventures we are currently involved in, we do not have a direct control over operations. When we participate in decisions as a joint venture partner, we must rely on the operator’s disclosure for all decisions. Furthermore, the operator is responsible for the day to day operations of the joint venture including technical operations, safety, environmental compliance, relationships with governments and vendors. As we do not have full control over the activities of our joint ventures, our results of operations are dependent upon the efforts of the operating partner.

We May Have Difficulty Distributing Our Production, Which Could Harm Our Financial Condition.

      To sell the oil and natural gas that we are able to produce, we have to make arrangements for storage and distribution to the market. We rely on local infrastructure and the availability of transportation for storage and shipment of our products, but infrastructure development and storage and transportation facilities may be insufficient for our needs at commercially acceptable terms in the localities in which we operate. This could be particularly problematic to the extent that our operations are conducted in remote areas that are difficult to access, such as areas that are distant from shipping and/or pipeline facilities. In certain areas, we may be required to rely on

only one gathering system, trucking company or pipeline, and, if so, our ability to market our production would be subject to their reliability and operations. These factors may affect our ability to explore and develop properties and to store and transport our oil and gas production and may increase our expenses.

     Furthermore, future instability in one or more of the countries in which we will operate, weather conditions or natural disasters, actions by companies doing business in those countries, labor disputes or actions taken by the international community may impair the distribution of oil and/or natural gas and in turn diminish our financial condition or ability to maintain our operations.

Our Oil Sales Will Depend on a Relatively Small Group of Customers, Which Could Adversely Affect Our Financial Results

     The entire Argentine domestic refining market is small and export opportunities are limited by available infrastructure. As a result, our oil sales in Argentina will depend on a relatively small group of customers, and currently, on just one customer in the area of our activity in the country. During 2006, we sold all of our production in Argentina to Refinor S.A. The lack of competition in this market could result in unfavorable sales terms which, in turn, could adversely affect our financial results.

     Oil sales in Colombia are made to Ecopetrol, a government agency. While oil prices in Colombia are related to international market prices, lack of competition for sales of oil may diminish prices and depress our financial results.

Drilling Oil and Gas Wells and Production and Transportation Activity Could be Hindered by Hurricanes, Earthquakes and Other Weather-Related Operating Risks.

     We are subject to operating hazards normally associated with the exploration and production of oil and gas, including blowouts, explosions, oil spills, cratering, pollution, earthquakes, hurricanes, labor disruptions and fires. The occurrence of any such operating hazards could result in substantial losses to us due to injury or loss of life and damage to or destruction of oil and gas wells, formations, production facilities or other properties. During November and December of 2005, our operations in Argentina were negatively effected by heavy rains and flooding in Northern Argentina. This caused trucking delays which prevented delivery of oil to the refinery for several days.

     As the majority of current oil production in Argentina is trucked to a local refinery, sales of oil can be delayed by adverse weather and road conditions. While storage facilities are designed to accommodate ordinary disruptions without curtailing production, delayed sales will delay revenues and may adversely impact the company’s working capital position. Furthermore, a prolonged disruption in oil deliveries could exceed storage capacities and shut-in production, which could have a negative impact on future production capability.

     All of our current oil production in Colombia is transported by an export pipeline which provides the only access to markets for our oil. Without other transportation alternatives, sales of oil could be disrupted by landslides or other natural events which impact this pipeline.

Prices and Markets for Oil and Natural Gas Are Unpredictable and Tend to Fluctuate Significantly, Which Could Reduce Profitability, Growth and the Value of Gran Tierra.

     Oil and natural gas are commodities whose prices are determined based on world demand, supply and other factors, all of which are beyond our control. World prices for oil and natural gas have fluctuated widely in recent years. The average price for West Texas Intermediate oil in 2000 was $30 per barrel. In 2006, it was $66 per barrel. We expect that prices will fluctuate in the future. Price fluctuations will have a significant impact upon our revenue, the return from our reserves and on our financial condition generally. Price fluctuations for oil and natural gas commodities may also impact the investment market for companies engaged in the oil and gas industry. Although during 2007 market prices for oil and natural gas have remained at high levels, these prices may not remain at current levels. Furthermore, prices which we receive for our oil sales, while based on international oil prices, are established by contract with purchasers with prescribed deductions for transportation and quality differences. These differentials can change over time and have a detrimental impact on realized prices. Future decreases in the prices of oil and natural gas may have a material adverse effect on our financial condition, the future results of our operations and quantities of reserves recoverable on an economic basis.

Our Foreign Operations Involve Substantial Costs and are Subject to Certain Risks Because the Oil and Gas Industries in the Countries in Which We Operate are Less Developed.

     The oil and gas industry in South America is not as efficient or developed as the oil and gas industry in North America. As a result, our exploration and development activities may take longer to complete and may be more expensive than similar operations in North America. The availability of technical expertise, specific equipment and supplies may be more limited than in North America. We expect that such factors will subject our international operations to economic and operating risks that may not be experienced in North American operations. In addition, oil and natural gas prices in Argentina are effectively regulated and as a result are substantially lower than those received in North America. Our average price for oil in Argentina in the first nine months of 2007 was $38.89 per barrel, net of royalties and selling costs compared to the average West Texas Intermediate price of $66.78 per barrel for the period. Oil prices in Colombia are related to international market prices, but adjustments that are defined by contract with Ecopetrol, a government agency and the purchaser of all oil that we produce in Colombia, may cause realized prices to be lower than those received in North America, meaning that our revenue and gross profit may be lower compared to similar production levels in North America. Our average oil price in Colombia in the first nine months of 2007 was $58.26 per barrel, net of royalties and selling costs.

Negative Economic, Political and Regulatory Developments in Argentina, Including Export Controls May Negatively Affect our Operations.

     The Argentine economy has experienced volatility in recent decades. This volatility has included periods of low or negative growth and variable levels of inflation. Inflation was at its peak in the 1980’s and early 1990’s. In late-2001 there was a deep fiscal crisis in Argentina involving restrictions on banking transactions, imposition of exchange controls, suspension of payment of Argentina’s public debt and abrogation of the one-to-one peg of the peso to the dollar. For the next year, Argentina experienced contractions in economic growth, increasing inflation and a volatile exchange rate. Currently, GDP is growing, inflation is normalized, and public finances are strengthened. However, there is no guarantee of economic stability. Any de-stabilization may seriously impact the economic viability of operations in the country or restrict the movement of cash into and out of the country, which would impair current activity and constrain growth in the country.

     On June 3, 2002, the Argentine government issued a resolution authorizing the Energy Secretariat to limit the amount of crude oil that companies can export. The restriction was to be in place from June 2002 to September 2002. However, on June 14, 2002, the government agreed to abandon the limit on crude export volumes in exchange for a guarantee from oil companies that domestic demand will be supplied. Oil companies also agreed not to raise natural gas and related prices to residential customers during the winter months and to maintain gasoline, natural gas and oil prices in line with those in other South American countries. Any future regulations that limit the amount of oil and gas that we could sell or any regulations that limit price increases in Argentina and elsewhere could severely limit the amount of our revenue and affect our results of operations.

The United States Government May Impose Economic or Trade Sanctions on Colombia That Could Result In A Significant Loss To Us.

Colombia is among several nations whose progress in stemming the production and transit of illegal drugs is subject to annual certification by the President of the United States. Although Colombia has received a 2006 certification, there can be no assurance that, in the future, Colombia will receive certification or a national interest waiver. The failure to receive certification or a national interest waiver may result in any of the following:

	•		all bilateral aid, except anti-narcotics and humanitarian aid, would be suspended,
	•		the Export-Import Bank of the United States and the Overseas Private Investment Corporation would not approve financing for new projects in Colombia,
	•		United States representatives at multilateral lending institutions would be required to vote against all loan requests from Colombia , although such votes would not constitute vetoes, and
	•		the President of the United States and Congress would retain the right to apply future trade sanctions.

     Each of these consequences could result in adverse economic consequences in Colombia and could further heighten the political and economic risks associated with our operations there. Any changes in the holders of significant government offices could have adverse consequences on our relationship with the Colombian national oil company and the Colombian government’s ability to control guerrilla activities and could exacerbate the factors relating to our foreign operations. Any sanctions imposed on Colombia by the United States government could threaten our ability to obtain necessary financing to develop the Colombian properties or cause Colombia to retaliate against us, including by nationalizing our Argosy assets. Accordingly, the imposition of the foregoing economic and trade sanctions on Colombia would likely result in a substantial loss and a decrease in the price of our common stock. There can be no assurance that the United States will not impose sanctions on Colombia in the future, nor can we predict the effect in Colombia that these sanctions might cause.

Guerrilla Activity in Colombia Could Disrupt or Delay Our Operations, and We Are Concerned About Safeguarding Our Operations and Personnel in Colombia.

     A 40-year armed conflict between government forces and anti-government insurgent groups and illegal paramilitary groups - both funded by the drug trade - continues in Colombia. Insurgents continue to attack civilians and violent guerilla activity continues in many parts of the country.

     We, through our acquisition of Argosy Energy International, have interests in three regions of Colombia - in the Middle Magdalena, Llanos and Putumayo regions. The Putumayo region has been prone to guerilla activity in the past. In 1989, Argosy’s facilities in one field were attacked by guerillas and operations were briefly disrupted. Pipelines have also been targets, including the Trans-Andean export pipeline which transports oil from the Putumayo region.

     There can be no assurance that continuing attempts to reduce or prevent guerilla activity will be successful or that guerilla activity will not disrupt our operations in the future. There can also be no assurance that we can maintain the safety of our operations and personnel in Colombia or that this violence will not affect our operations in the future. Continued or heightened security concerns in Colombia could also result in a significant loss to us.

Increases in Our Operating Expenses will Impact Our Operating Results and Financial Condition.

     Exploration, development, production, marketing (including distribution costs) and regulatory compliance costs (including taxes) will substantially impact the net revenues we derive from the oil and gas that we produce. These costs are subject to fluctuations and variation in different locales in which we will operate, and we may not be able to predict or control these costs. If these costs exceed our expectations, this may adversely affect our results of operations. In addition, we may not be able to earn net revenue at our predicted levels, which may impact our ability to satisfy our obligations.

Penalties We May Incur Could Impair Our Business.

     Our exploration, development, production and marketing operations are regulated extensively under foreign, federal, state and local laws and regulations. Under these laws and regulations, we could be held liable for personal injuries, property damage, site clean-up and restoration obligations or costs and other damages and liabilities. We may also be required to take corrective actions, such as installing additional safety or environmental equipment, which could require us to make significant capital expenditures. Failure to comply with these laws and regulations may also result in the suspension or termination of our operations and subject us to administrative, civil and criminal penalties, including the assessment of natural resource damages. We could be required to indemnify our employees in connection with any expenses or liabilities that they may incur individually in connection with regulatory action against them. As a result of these laws and regulations, our future business prospects could deteriorate and our profitability could be impaired by costs of compliance, remedy or indemnification of our employees, reducing our profitability.

Environmental Risks May Adversely Affect Our Business.

     All phases of the oil and natural gas business present environmental risks and hazards and are subject to environmental regulation pursuant to a variety of international conventions and federal, provincial and municipal

laws and regulations. Environmental legislation provides for, among other things, restrictions and prohibitions on spills, releases or emissions of various substances produced in association with oil and gas operations. The legislation also requires that wells and facility sites be operated, maintained, abandoned and reclaimed to the satisfaction of applicable regulatory authorities. Compliance with such legislation can require significant expenditures and a breach may result in the imposition of fines and penalties, some of which may be material. Environmental legislation is evolving in a manner we expect may result in stricter standards and enforcement, larger fines and liability and potentially increased capital expenditures and operating costs. The discharge of oil, natural gas or other pollutants into the air, soil or water may give rise to liabilities to foreign governments and third parties and may require us to incur costs to remedy such discharge. The application of environmental laws to our business may cause us to curtail our production or increase the costs of our production, development or exploration activities.

Our Insurance May Be Inadequate to Cover Liabilities We May Incur.

     Our involvement in the exploration for and development of oil and natural gas properties may result in our becoming subject to liability for pollution, blow-outs, property damage, personal injury or other hazards. Although we will obtain insurance in accordance with industry standards to address such risks, such insurance has limitations on liability that may not be sufficient to cover the full extent of such liabilities. In addition, such risks may not, in all circumstances be insurable or, in certain circumstances, we may choose not to obtain insurance to protect against specific risks due to the high premiums associated with such insurance or for other reasons. The payment of such uninsured liabilities would reduce the funds available to us. If we suffer a significant event or occurrence that is not fully insured, or if the insurer of such event is not solvent, we could be required to divert funds from capital investment or other uses towards covering our liability for such events.

Our Business is Subject to Local Legal, Political and Economic Factors Which are Beyond Our Control, Which Could Impair Our Ability to Expand Our Operations or Operate Profitably.

     We expect to operate our business in Argentina, Colombia and Peru, and to expand our operations into other countries in the world. Exploration and production operations in foreign countries are subject to legal, political and economic uncertainties, including terrorism, military repression, interference with private contract rights (such as privatization), extreme fluctuations in currency exchange rates, high rates of inflation, exchange controls and other laws or policies affecting environmental issues (including land use and water use), workplace safety, foreign investment, foreign trade, investment or taxation, as well as restrictions imposed on the oil and natural gas industry, such as restrictions on production, price controls and export controls. Central and South America have a history of political and economic instability. This instability could result in new governments or the adoption of new policies, laws or regulations that might assume a substantially more hostile attitude toward foreign investment. In an extreme case, such a change could result in termination of contract rights and expropriation of foreign-owned assets. Any changes in oil and gas or investment regulations and policies or a shift in political attitudes in Argentina, Colombia, Peru or other countries in which we intend to operate are beyond our control and may significantly hamper our ability to expand our operations or operate our business at a profit.

     For instance, changes in laws in the jurisdiction in which we operate or expand into with the effect of favoring local enterprises, changes in political views regarding the exploitation of natural resources and economic pressures may make it more difficult for us to negotiate agreements on favorable terms, obtain required licenses, comply with regulations or effectively adapt to adverse economic changes, such as increased taxes, higher costs, inflationary pressure and currency fluctuations.

Local Legal and Regulatory Systems in Which We Operate May Create Uncertainty Regarding Our Rights and Operating Activities, Which May Harm Our Ability to do Business.

     We are a company organized under the laws of the State of Nevada and are subject to United States laws and regulations. The jurisdictions in which we intend to operate our exploration, development and production activities may have different or less developed legal systems than the United States, which may result in risks such as:

•

effective legal redress in the courts of such jurisdictions, whether in respect of a breach of law or regulation, or, in an ownership dispute, being more difficult to obtain;

	•		a higher degree of discretion on the part of governmental authorities;
	•		the lack of judicial or administrative guidance on interpreting applicable rules and regulations;
	•		inconsistencies or conflicts between and within various laws, regulations, decrees, orders and resolutions; and
	•		relative inexperience of the judiciary and courts in such matters.

In certain jurisdictions the commitment of local business people, government officials and agencies and the judicial system to abide by legal requirements and negotiated agreements may be more uncertain, creating particular concerns with respect to licenses and agreements for business. These licenses and agreements may be susceptible to revision or cancellation and legal redress may be uncertain or delayed. Property right transfers, joint ventures, licenses, license applications or other legal arrangements pursuant to which we operate may be adversely affected by the actions of government authorities and the effectiveness of and enforcement of our rights under such arrangements in these jurisdictions may be impaired.

We are Required to Obtain Licenses and Permits to Conduct Our Business and Failure to Obtain These Licenses Could Cause Significant Delays and Expenses That Could Materially Impact Our Business.

     We are subject to licensing and permitting requirements relating to drilling for oil and natural gas. We cannot assure you that we will be able to obtain, sustain or renew such licenses. We cannot assure you that regulations and policies relating to these licenses and permits will not change or be implemented in a way that we do not currently anticipate. These licenses and permits are subject to numerous requirements, including compliance with the environmental regulations of the local governments. As we are not the operator of all the joint ventures we are currently involved in, we may rely on the operator to obtain all necessary permits and licenses. If we fail to comply with these requirements, we could be prevented from drilling for oil and natural gas, and we could be subject to civil or criminal liability or fines. Revocation or suspension of our environmental and operating permits could have a material adverse effect on our business, financial condition and results of operations.

Challenges to Our Properties May Impact Our Financial Condition.

     Title to oil and natural gas interests is often not capable of conclusive determination without incurring substantial expense. While we intend to make appropriate inquiries into the title of properties and other development rights we acquire, title defects may exist. In addition, we may be unable to obtain adequate insurance for title defects, on a commercially reasonable basis or at all. If title defects do exist, it is possible that we may lose all or a portion of our right, title and interest in and to the properties to which the title defects relate.

     Furthermore, applicable governments may revoke or unfavorably alter the conditions of exploration and development authorizations that we procure, or third parties may challenge any exploration and development authorizations we procure. Such rights or additional rights we apply for may not be granted or renewed on terms satisfactory to us.

     If our property rights are reduced, whether by governmental action or third party challenges, our ability to conduct our exploration, development and production may be impaired.

Foreign Currency Exchange Rate Fluctuations May Affect Our Financial Results.

     We expect to sell our oil and natural gas production under agreements that will be denominated in United States dollars and foreign currencies. Many of the operational and other expenses we incur will be paid in the local currency of the country where we perform our operations. Our production is primarily invoiced in United States dollars, but payment is also made in Argentine and Colombian pesos, at the then-current exchange rate. As a result, we are exposed to translation risk when local currency financial statements are translated to United States dollars, our company’s functional currency. Since we began operating in Argentina (September 1, 2005), the rate of exchange between the Argentine peso and US dollar has varied between 2.89 pesos to one US dollar to 3.23 pesos to the US dollar, a fluctuation

of approximately 11%. Exchange rates between the Colombian peso and US dollar have varied between 1,914 pesos to one US dollar to 2,640 pesos to one US dollar since September 1, 2005, a fluctuation of approximately 28%. As currency exchange rates fluctuate, translation of the statements of income of international businesses into United States dollars will affect comparability of revenues and expenses between periods.

Exchange Controls and New Taxes Could Materially Affect our Ability to Fund Our Operations and Realize Profits from Our Foreign Operations.

     Foreign operations may require funding if their cash requirements exceed operating cash flow. To the extent that funding is required, there may be exchange controls limiting such funding or adverse tax consequences associated with such funding. In addition, taxes and exchange controls may affect the dividends that we receive from foreign subsidiaries.

     Exchange controls may prevent us from transferring funds abroad. For example, the Argentine government has imposed a number of monetary and currency exchange control measures that include restrictions on the free disposition of funds deposited with banks and tight restrictions on transferring funds abroad, with certain exceptions for transfers related to foreign trade and other authorized transactions approved by the Argentine Central Bank. We cannot assure you that the Central Bank will not require prior authorization or will grant such authorization for our Argentine subsidiaries to make dividend payments to us and we cannot assure you that there will not be a tax imposed with respect to the expatriation of the proceeds from our foreign subsidiaries.

We Will Rely on Technology to Conduct Our Business and Our Technology Could Become Ineffective Or Obsolete.

     We rely on technology, including geographic and seismic analysis techniques and economic models, to develop our reserve estimates and to guide our exploration and development and production activities. We will be required to continually enhance and update our technology to maintain its efficacy and to avoid obsolescence. The costs of doing so may be substantial, and may be higher than the costs that we anticipate for technology maintenance and development. If we are unable to maintain the efficacy of our technology, our ability to manage our business and to compete may be impaired. Further, even if we are able to maintain technical effectiveness, our technology may not be the most efficient means of reaching our objectives, in which case we may incur higher operating costs than we would were our technology more efficient.

Risks Related to Our Common Stock

The Market Price of Our Common Stock May Be Highly Volatile and Subject to Wide Fluctuations.

 The market price of our common stock may be highly volatile and could be subject to wide fluctuations in response to a number of factors that are beyond our control, including:

	•		dilution caused by our issuance of additional shares of common stock and other forms of equity securities, which we expect to make in connection with future capital financings to fund our operations and growth, to attract and retain valuable personnel and in connection with future strategic partnerships with other companies;
	•		announcements of new acquisitions, reserve discoveries or other business initiatives by our competitors;
	•		fluctuations in revenue from our oil and natural gas business as new reserves come to market;
	•		changes in the market for oil and natural gas commodities and/or in the capital markets generally;
	•		changes in the demand for oil and natural gas, including changes resulting from the introduction or expansion of alternative fuels; and
	•		changes in the social, political and/or legal climate in the regions in which we will operate.

In addition, the market price of our common stock could be subject to wide fluctuations in response to:

	•		quarterly variations in our revenues and operating expenses;
	•		changes in the valuation of similarly situated companies, both in our industry and in other industries;
	•		changes in analysts’ estimates affecting our company, our competitors and/or our industry;
	•		changes in the accounting methods used in or otherwise affecting our industry;
	•		additions and departures of key personnel;
	•		announcements of technological innovations or new products available to the oil and natural gas industry;
	•		announcements by relevant governments pertaining to incentives for alternative energy development programs;
	•		fluctuations in interest rates, exchange rates and the availability of capital in the capital markets; and
	•		significant sales of our common stock, including sales by the investors following registration of the shares of common stock under the registration statement of which this prospectus is a part and/or future investors in future offerings we expect to make to raise additional capital.

     These and other factors are largely beyond our control, and the impact of these risks, singularly or in the aggregate, may result in material adverse changes to the market price of our common stock and/or our results of operation and financial condition.

Our Operating Results May Fluctuate Significantly, and These Fluctuations May Cause Our Stock Price to Decline.

     Our operating results will likely vary in the future primarily from fluctuations in our revenues and operating expenses, including the coming to market of oil and natural gas reserves that we are able to develop, expenses that we incur, the prices of oil and natural gas in the commodities markets and other factors. If our results of operations do not meet the expectations of current or potential investors, the price of our common stock may decline.

We Do Not Expect to Pay Dividends In the Foreseeable Future.

     We do not intend to declare dividends for the foreseeable future, as we anticipate that we will reinvest any future earnings in the development and growth of our business. Therefore, investors will not receive any funds unless they sell their common stock, and stockholders may be unable to sell their shares on favorable terms or at all. Investors cannot be assured of a positive return on investment or that they will not lose the entire amount of their investment in our common stock.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

     This prospectus contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). This prospectus includes statements regarding our plans, goals, strategies, intent, beliefs or current expectations. These statements are expressed in good faith and based upon a reasonable basis when made, but there can be no assurance that these expectations will be achieved or accomplished. These forward looking statements can be identified by the use of terms and phrases such as “believe,” “plan,” “intend,” “anticipate,” “target,” “estimate,” “expect,” and the like, and/or future-tense or conditional constructions “may,” “could,” “should,” etc. Items contemplating or making assumptions about, actual or potential future sales, market size, collaborations, and trends or operating results also constitute such forward-looking statements.

     Although forward-looking statements in this prospectus reflect the good faith judgment of our management, forward-looking statements are inherently subject to known and unknown risks, business, economic and other risks and uncertainties that may cause actual results to be materially different from those discussed in these forward-looking statements. Readers are urged not to place undue reliance on these forward-looking statements, which speak only as of the date of this prospectus. We assume no obligation to update any forward-looking statements in order to reflect any event or circumstance that may arise after the date of this prospectus, other than as may be required by applicable law or regulation. Readers are urged to carefully review and consider the various disclosures made by us in our reports filed with the Securities and Exchange Commission which attempt to advise interested parties of the risks and factors that may affect our business, financial condition, results of operation and cash flows. If one or more of these risks or uncertainties materialize, or if the underlying assumptions prove incorrect, our actual results may vary materially from those expected or projected.

DIVIDEND POLICY

     We have never declared or paid any dividends on our capital stock. We currently intend to retain any future earnings to fund the development and expansion of our business, and therefore we do not anticipate paying cash dividends on our common stock in the foreseeable future. Any future determination to pay dividends will be at the discretion of our board of directors. In addition, under the terms of our credit facility with Standard Bank Plc, we are required to obtain the approval of the Bank for any dividend payments made by us exceeding $2 million in any fiscal year.

USE OF PROCEEDS

     We will not receive any proceeds from the sale by the selling stockholders of our common stock. We will receive approximately $3,067,000 if three of the selling stockholders exercise their warrants in full. The warrant holders may exercise their warrants at any time until their expiration, as further described in the “Description of Securities.” Because the warrant holders may exercise the warrants in their own discretion, we cannot plan on specific uses of proceeds beyond application of proceeds to general corporate purposes. These proceeds will be used for general corporate purposes and capital expenditures. We will bear the expenses in connection with the registration of the common stock being offered hereby by the selling stockholders.

PRICE RANGE OF COMMON STOCK

     Our common stock was first cleared for quotation on the OTC bulletin board on November 11, 2005 and has been trading since that time under the symbol “GTRE.OB.”

     As of November 15, 2007 there were approximately 418 holders of record of shares of our common stock (including holders of exchangeable shares).

     On December 19, 2007, the last reported sales price of our shares on the OTC bulletin board was $2.13. For the periods indicated, the following table sets forth the high and low bid prices per share of common stock. These prices represent inter-dealer quotations without retail markup, markdown, or commission and may not necessarily represent actual transactions.

		High				Low
Fourth Quarter (through December 19, 2007)		$	2.22			$	1.39
Third Quarter		$	2.16			$	1.31
Second Quarter		$	1.49			$	0.90
First Quarter 2007		$	1.64			$	0.88
Fourth Quarter 2006		$	1.75			$	1.10
Third Quarter 2006		$	3.67			$	1.47
Second Quarter 2006		$	5.01			$	2.96
First Quarter 2006		$	5.95			$	3.02
November 11 through Dec 2005		$	2.80			$	1.50

     As of November 15, 2007, there are 95,051,909 shares of common stock issued and outstanding, which number includes shares of common stock issuable upon exchange of the exchangeable shares of Goldstrike Exchange Co. issued to former holders of Gran Tierra Canada’s common stock.

     Equity Compensation Plan

     Securities authorized for issuance under equity compensation plans as of December 31, 2006 are as follows:

		Number of				Weighted				Number of securities
		securities to be issued upon				average exercise price of				remaining available for future
Plan category		exercise of options				outstanding options				issuance
Equity compensation plans approved by security holders			1,520,000			$	1.12				480,000
Equity compensation plans not approved by security holders			1,180,000			$	1.27				—
Total			2,700,000								480,000

     The only equity compensation plan approved by our stockholders is our 2005 Equity Incentive Plan, under which our board of directors is authorized to issue options or other rights to acquire up to 2,000,000 shares of our common stock. On November 8, 2006, our board of directors granted options to acquire 1,180,000 shares of common stock at an exercise price of $1.27 per share, which options cannot be exercised, and will be rescinded, if our stockholders do not approve an increase in the number of shares authorized under the 2005 Equity Incentive Plan sufficient to permit the issuance of the shares issuable upon exercise of these additional stock options. These stock options are reflected in the table above as not being approved by security holders. In addition, in 2007 through May 2, 2007, the Board granted options to acquire an additional 850,000 shares of common stock at a weighted average exercise price of $1.25 per share, which options cannot be exercised, and will be rescinded, if our stockholders do not approve an increase in the number of shares authorized under the 2005 Equity Incentive Plan sufficient to permit the issuance of the shares issuable upon exercise of these additional stock options.

SELECTED FINANCIAL DATA

     The following selected summary consolidated financial data should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and audited financial statements as at and for the years ended December 31, 2005 and 2006, and unaudited financial statements as at and for the nine months ended September 30, 2006 and 2007, included in this prospectus. Our results of operations in 2005 are for the period of incorporation, which was January 26, 2005, to December 31, 2005. All dollar amounts are in US dollars.

		Year Ended December 31,								Nine Months ended September 30,
		2005				2006				2006				2007
		(Audited)								(Unaudited)
Results of Operations
Revenues
Oil sales		$	946,098			$	11,645,553			$	8,293,620			$	15,892,368
Natural gas sales			113,199				75,488				65,301				35,494
Interest			—				351,872				195,816				377,432
Total revenues			1,059,297				12,072,913				8,554,737				16,305,294
Expenses
Operating			395,287				4,233,470				2,702,507				6,719,453
Depletion, depreciation and accretion			462,119				4,088,437				2,324,158				6,549,852
General and administrative			2,482,070				6,998,805				3,998,196				7,583,721
Liquidated damages			—				1,527,988				261,182				7,366,949
Derivative financial instruments			—				—				—				793,580
Foreign exchange (gain) loss			(31,271	)			370,538				277,526				(91,772	)
Total expenses			3,308,205				17,219,237				9,563,569				28,921,783
Loss before income tax			(2,248,908	)			(5,146,324	)			(1,008,832	)			(12,616,489	)
Income tax			29,228				(677,380	)			848,200				(1,985,918	)
Net loss		$	(2,219,680	)		$	(5,823,704	)		$	(1,857,032	)		$	(10,630,571	)
Net loss per common share – basic and diluted		$	(0.16	)		$	(0.08	)		$	(0.03	)		$	(0.11	)
Cash Flows
Operating activities		$	(1,876,638	)		$	(829,618	)		$	2,223,931			$	(1,314,953	)
Investing activities			(9,108,022	)			(46,672,884	)			(56,475,440	)			(15,164,409	)
Financing activities			13,206,116				69,381,827				70,826,137				426,983
Increase (decrease) in cash		$	2,221,456			$	21,879,325			$	16,574,628			$	(16,052,379	)
		December 31,								September 30,
		2005				2006				2006				2007
Financial Position
Cash and cash equivalents		$	2,221,456			$	24,100,780			$	18,796,084			$	8,048,401
Working capital			2,764,643				14,274,644				29,822,496				9,313,180
Total assets			12,371,131				105,910,809				99,207,620				101,876,428
Deferred tax liability			—				9,875,657				7,849,421				10,500,817
Other long-term Liabilities			67,732				740,681				1,583,651				3,247,769
Shareholders equity			11,039,347				76,194,779				80,211,760				73,971,873

     We made our initial acquisition of oil and gas producing and non-producing properties in Argentina in September 2005 for a total purchase price of approximately $7 million. Prior to that time we had no revenues. In June 2006, we acquired our Argosy assets for consideration of $37.5 million cash, 870,647 shares of our common stock and overriding and net profit interests in certain assets valued at $1 million. See “Business” for a description of these acquisitions.

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

     The following discussion of our financial condition and results of operations should be read in conjunction with our consolidated financial statements and notes thereto. Except for the historical information contained herein, the matters discussed below are forward-looking statements that involve risks and uncertainties, including, among others, the risks and uncertainties discussed below.

Overview

     We are an independent international energy company involved in oil and natural gas exploration, development and production. We plan to continually increase our oil and natural gas reserves through a balanced strategy of exploration drilling, development and acquisitions in South America. Initial countries of interest are Argentina, Colombia and Peru.

     We took our current form on November 10, 2005 when the former Gran Tierra Energy Inc, a privately held corporation in Alberta (“Gran Tierra Canada”), was acquired by an indirect subsidiary of Goldstrike Inc, a Nevada corporation, which was publicly traded on the OTC Bulletin Board. Goldstrike adopted the assets, management, business operations, business plan and name of Gran Tierra Canada. The predecessor company in the transaction was the former Gran Tierra Canada; the financial information of the former Goldstrike was eliminated at consolidation. This transaction is accounted for as a reverse takeover of Goldstrike Inc. by Gran Tierra Canada. We currently intend to list on one or more foreign or domestic stock exchanges; however, there is no assurance that we will be able to do so.

     Prior to September 1, 2005, we had no oil and gas interests or properties. In September 2005 and during 2006 we acquired oil and gas interests and properties in Argentina, Colombia and Peru.

     On September 1, 2005, we acquired a 14% non-operating interest in the Palmar Largo joint venture in Argentina, involving several producing fields. At the same time, we acquired interests in two minor properties in Argentina, comprising a 50% interest in the Nacatimbay block, which produces minor volumes of natural gas and associated liquids from a single well, and a 50% interest in the Ipaguazu block, a non-producing property. The total cost of these acquisitions was approximately $7 million.

     Effective June 30, 2006, we closed a farm-in arrangement with Golden Oil Corporation whereby we purchased 50% of the El Vinalar producing block in Argentina for $950,000. We also agreed to pay 100% of the first $2.7 million in costs of a sidetrack well related to this farm-in agreement.

     On February 15, 2006, we made an offer to acquire the interests of CGC in eight properties in Argentina. On November 2, 2006, we closed the purchase of interests in four properties for a total purchase price of $2.1 million. The assets purchased include a 93.18% participation interest in the Valle Morado block, a 100% interest in the Santa Victoria block and the remaining 50% interests in the Nacatimbay and Ipaguazu blocks.

     On December 1, 2006, we closed the purchase of interests in two other properties from CGC, including a 100% interest in the El Chivil block and a 100% participation interest in the Surubi block, each located in the Noroeste Basin of Argentina, for a total purchase price of $2.5 million. We also purchased the remaining 25% minority interest in each property from the joint venture partner for a total purchase price of $280,000.

     The total purchase price in 2006 for the acquisition of CGC’s interests in all six properties was $4.6 million. Post-closing adjustments, which reflect original values assigned to the properties, amended terms, revenues and costs from the effective date of January 1, 2006, were approximately $3.8 million which was paid in January 2007.

     We began operations in Colombia on June 20, 2006 through the acquisition of Argosy Energy International L.P. (“Argosy”). The Argosy assets consist of interests in a portfolio of producing and non-producing assets in Colombia. We entered into a Securities Purchase Agreement dated May 25, 2006 with Crosby Capital LLC to acquire all of the limited partnership interests of Argosy and all of the issued and outstanding capital stock of Argosy Energy Corp. On June 20, 2006 we closed the Argosy acquisition and paid consideration to Crosby consisting of $37.5 million cash, 870,647 shares of our common stock and overriding and net profit interests in certain of Argosy’s assets valued at $1 million. The value of the overriding and net profit interests was based on present value of expected future cash flows.

     We signed a License Contract with PeruPetro S.A. for the Exploration and Exploitation of Hydrocarbons covering Block 122 in Peru on June 8, 2006. Terms of the License define a seven-year exploration term with four periods, each with minimum work obligations. The minimum commitment for the first work period, which is mandatory, is $0.5 million. The potential commitment over the seven-year period, at our option, is $5.0 million and includes technical studies, seismic acquisition and the drilling of one exploration well. The License Contract defines an exploitation term of thirty years for commercial discoveries of oil. Block 122 covers 1.2 million acres. Final ratification by the government of Peru occurred on November 3, 2006. A second License Contract for the adjacent Block 128 was subsequently awarded and ratified on December 12, 2006. This second License encompasses 2.2 million acres and has the same terms as that for Block 122.

     Acquisitions of properties in Colombia and Argentina were funded through a series of private placements of our securities that occurred between September 2005 and February 2006 and an additional private placement that occurred in June 2006.

     In the fourth quarter of 2005 and the first quarter of 2006 we sold 15 million units of our securities for gross proceeds of $12 million, less issue costs of $800,000, for net proceeds of $11.2 million. Each unit consisted of one share of common stock and a warrant to purchase one half of a common share for five years at an exercise price of $1.25 per whole share.

     In June, 2006 we sold 50,000,000 units of our securities for total proceeds of $75,000,000, less issue costs of $6,306,699, for net proceeds of $68,693,301. Each unit consisted of one share of common stock and one warrant to purchase one half a common share for five years at an exercise price of $1.75 per whole share.

     During the second quarter of 2007, investors holding 948,853 units, comprising 948,853 common shares and warrants to purchase 474,426 common shares, exercised their right to have us return to them their purchase price for the securities. The net proceeds from the sale of the securities amounting to $1,280,951, held in escrow by the Bank of America, were refunded to the investors to complete this transaction during June, 2007, and the securities were cancelled.

     The shares of common stock and warrants to purchase common shares issued in 2005 and 2006 have registration rights associated with their issuance pursuant to which we agreed to register for resale the shares and warrants. In the event that the registration statements were not declared effective by the SEC by specified dates, we were required to pay liquidated damages to the purchasers of the shares and warrants.

     The holders of units purchased in the 2005 and first quarter of 2006 offering were paid their full liquidated damages in cash in the amount of $269,923 in December 2006.

     On June 27, 2007, we agreed to amend the terms of the warrants issued in the June 2006 offering by reducing the exercise price of the warrants to $1.05 and extending the life of the warrants by one year. In doing so, the investors waived their rights to receive an aggregate cash payment of approximately $8,625,000 for the liquidated damages accrued.

     Effective February 28, 2007, we secured a $50 million credit facility with Standard Bank Plc. The credit facility has a three-year term and an initial borrowing base of $7 million. Funds available under our bank credit facility are limited to the amount of the borrowing base, as determined by the bank semi-annually. No amounts have been drawn-down under the facility.

     Our ability to continue as a going concern is dependent upon obtaining the necessary financing to acquire oil and natural gas interests and generating profitable operations from our oil and natural gas interests in the future. Our financial statements as at and for the year ended December 31, 2006 and as at and for the nine month period ended September 30, 2007 have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. We incurred a net loss of $5,823,704 for the year ended December 31, 2006, and, as at December 31, 2006, we had a deficit of $8,043,384. We incurred a net loss of $10,630,571 for the nine months ended September 30, 2007, and, as at September 30, 2007, we had a deficit of $18,673,955. We expect to incur substantial expenditures to further our capital investment programs and our cash flow from operating activities and current cash balances may not be sufficient to satisfy our current obligations and meet our capital investment objectives. We intend to explore opportunities as they arise, including raising additional capital, pursuing acquisitions of assets or other companies or a merger with another company, and selling or co-partnering development of some of our assets, to achieve our financing needs. We may not be successful in such pursuits.

     To address our ability to continue as a going concern, we have raised additional capital through the sale and issuance of common shares, and may do so again in the future. We plan to expand our portfolio of production, development, step-out and exploration opportunities using additional equity financing, cash provided from future operating activities, and the bank credit facility. Additional equity financing may not be available to us on attractive terms, if at all. Further, funds available under our bank credit facility are limited to the amount of the borrowing base, as determined by the bank semi-annually, up to a maximum of $50 million and provided that we are able to make the required representations to our lender.

     We currently generate the majority of our revenue and cash flow from the production and sale of crude oil in Argentina and Colombia. The selling prices for our crude oil production are based on international oil prices, which historically have been volatile. In 2007, our production may be subject to natural production declines, and our revenues may be impacted by international oil prices, which are uncertain. Results from operations may also be affected by drilling efforts and planned remedial work programs. Our drilling and work plans for 2007 are expected to be funded from available cash, anticipated cash flow from operations, and a bank credit facility. Oil price declines combined with unexpected costs may require additional equity and/or debt financing during the year. Increases in the borrowing base under our credit facility are dependent on our success in increasing oil and gas reserves and dependent on future oil prices.

     Our financial results for 2005 and 2006 and the first nine months of 2007 are principally impacted by acquisitions of oil and gas interests in Argentina and Colombia in the third quarter of 2005 and the second and fourth quarters of 2006, as described above, which affected our results of operations. Our financial condition has also been affected by the equity financings described above.

     The operating results for 2006 include a full year of activities at Palmar Largo, two months at Nacatimbay before production was suspended on March 1 and two months after production was reinstated on November 1, six months of activities at El Vinalar beginning July 1, 2006 and one month of activities at Chivil, commencing December 1, and the Argosy acquisitions in Colombia from June 21, 2006. The operating results and financial position for 2005 reflect our incorporation on January 26, 2005 and the commencement of oil and gas operations in Argentina on September 1, 2005.

Results of Operations for the Nine Months ended September 30, 2007 and 2006

     The comparison of the financial and operational results for the nine months ended September 30, 2007 to the same period in 2006, is impacted primarily by the increases that occurred to our operational assets due to properties acquired during 2006 and as a result of recent increased production from two new oil field discoveries in Colombia.

     In Argentina, we initially held a 14% working interest (WI) in Palmar Largo (oil production), a 50% WI in Nacatimbay (production of natural gas and condensate) and a 50% WI in Ipaguazu (exploration land). These assets are reflected in the results for the nine month period ended September 30, 2006. During November and December of 2006 we acquired the following additional working interests in Argentina, which further impacted the financial and operational results for the nine month period ended September 30, 2007.

Ø an additional 50% WI in Nacatimbay

Ø an additional 50% WI in Ipaguazu

Ø 50% WI in El Vinalar (oil production)

Ø 100% WI in Chivil (oil production)

Ø 100% WI in Surubi (exploration land)

Ø 100% WI in Santa Victoria (exploration land)

Ø 93.2% WI in Valle Morado (exploration land)

     As a result of the completion of an independent reserve audit by reserve auditors and internal assessments relating to our exploration and drilling program in the first half of 2007, we have increased our proved reserves.

     For the Costayaco oil discovery, our independent reserve auditors have allocated to us proved reserves of 2.7 million barrels of oil. The discovery of the Costayaco field in the Chaza Block, located in the Putumayo Basin of Colombia, was the result of drilling the Costayaco-1 exploration well in the second quarter of 2007.

     For the Juanambu discovery, our independent reserve auditors have allocated to us proved reserves of 0.1 million barrels of oil. The discovery of the Juanambu field in the Guayuyaco Block, also located in the Putumayo Basin of Colombia, was the result of drilling the Juanambu-1 exploration well early in 2007.

     As a result of the adjustments and production for the first nine months of 2007, our estimate of proved reserves, net of royalties, as of September 30, 2007, stands at 5.4 million barrels of oil. This contrasts to our December 31, 2006 proved reserves of 3.0 million barrels of oil.

     In Colombia, production from our new discovery wells Costayaco-1 and Juanambu-1 increased daily production by 414 barrels per day over the prior quarter, 453 barrels per day over the same quarter in the prior year and 166 barrels per day over the same nine month period ended September 30, 2006.

     Prior to June 20, 2006 we did not own any properties in Colombia. On June 20, 2006 we acquired Argosy Energy International L.P. and became the operator of nine blocks in Colombia. The Santana and Guayuyaco blocks are currently producing. The Rio Magdalena, Talora, Chaza, Primavera, Azar and Mecaya blocks are in their exploration phases. The addition of these assets to our portfolio impacted the results for the nine months ended September 30, 2007 as compared to the prior year same period.

Revenues and Other Income

		Nine months ended
		September 30,								Change from
		2007				2006				prior period
Oil Sales		$	15,892,368			$	8,293,620			$	7,598,748
Natural Gas Sales			35,494				65,301				(29,807	)
Interest and Other			377,432				195,816				181,616
Total		$	16,305,294			$	8,554,737			$	7,750,557

     The increase in revenue realized in the nine month period ended September 30, 2007 as compared to the prior year period is attributed primarily to the additional properties acquired during 2006 and recent increased production from two new oil field discoveries in Colombia. Although interest income increased in the nine month period ended September 30, 2007 over the same period in 2006, decreasing cash balances over 2007 as we executed our capital expenditure program have resulted in lower interest income earned in the third quarter of 2007 as compared to the same period in 2006. The cash balances were sourced from the June 2006 private equity issuance.

     In Argentina, crude oil production after 12% royalties for the nine month period ended September 30, 2007 was 160,599 barrels, compared to 82,719 barrels, for the nine month period ended September 30, 2006. The difference in production can be primarily attributed to the additional properties acquired during 2006 and the production from the Puesto Climaco-2 sidetrack well drilled in the first quarter of 2007.

     In Argentina, oil sales after 12% royalties were 150,676 barrels for the nine months ended September 30, 2007, compared to 104,286 barrels for the nine month period ended September 30, 2006. The difference between the results for the nine months ended September 30, 2007 and the same period in 2006 can be primarily attributed to the additional properties acquired during 2006 and the production from the Puesto Climaco-2 well.

     In Argentina, oil revenue, net of an average production royalty of 12 %, for the nine months ended September 30, 2007 was $5.9 million. Oil revenue for the same period in 2006 was $4.3 million. Our net loss before income tax from Argentina operations for the nine month period ended September 30, 2007 was $1.5 million, due primarily to planned workovers and maintenance activities compared to net income of $0.3 million for the corresponding period in 2006.

     Average sales price for oil sales during the nine months ended September 30, 2007 was $38.89 per barrel compared to $41.06 for the same period in 2006. Average sales prices at Nacatimbay for natural gas sales were $2.09 per Mcf for the nine months ended September 30, 2007

compared to $1.64 for the same period in 2006. Although oil pricing determination is based on West Texas Intermediate (“WTI”) price, oil and natural gas prices are effectively regulated in Argentina.

     In Colombia, production after royalties was 181,957 barrels for the nine months ended September 30, 2007. Following the acquisition on June 20, 2006 there was production of 72,618 barrels from Colombia for the same period during 2006. The 2006 production represents 102 days of production for the nine month period.

     In Colombia, sales after royalties were 172,228 barrels for the nine months ended September 30, 2007. For the same period in 2006, Colombian sales after royalties were 70,980 barrels.

     In Colombia, oil revenue, net of royalties, was $10.0 million for the nine month period ended September 30, 2007, reflecting royalty rates of 20% for the Santana block and 8% for the Guayuyaco, Juanambu, and Costayaco blocks. The average sales prices for oil during this period was $58.26 per barrel. Our segment income before tax from the Colombian operations was $2.2 million for the nine month period ended September 30, 2007. The increase was due to the impact of new well production in the Guayayaco and Chaza Blocks during the third quarter of 2007 with total production from these two blocks amounting to 42,385 barrels.

     We earned interest income of $377,432 in the nine month period in 2007 on our cash deposits from our financing in June 2006, compared to $195,816 in the corresponding 2006 period. The cash balances were sourced from the June 2006 private equity issuance.

     We expect our revenues to increase as we describe in “Liquidity and Capital Resources.”

Operating Expenses

		Nine Months ended
		September 30,								Increase from
		2007				2006				prior period
Operating Expenses		$	6,719,453			$	2,702,507			$	4,016,946
Cost per barrel		$	19.32			$	17.26			$	2.05

     The current year operating costs are higher than in the same period of 2006 due to workovers undertaken in the current year. Argentina’s operating costs were $27.10 per barrel for the nine months ended September 30, 2007 representing budgeted workover costs undertaken to sustain production. Colombia’s operating costs were $10.76 per barrel for the nine months ended September 30, 2007. Colombia’s operating costs were $7.27 per barrel for the three and nine months ended September 30, 2006. The current year operating costs are higher than in the same periods of 2006 due to workovers undertaken in the current year.

     We expect our operating costs to increase as we describe in “Liquidity and Capital Resources.”

Depletion, depreciation and accretion

		Nine Months ended
		September 30,								Increase from
		2007				2006				prior period
Cost		$	6,549,852			$	2,324,158			$	4,225,694

     The increase in depletion, depreciation and accretion expense reflect the addition of properties acquired in Colombia and Argentina during 2006 and their associated increased production in 2007 over the previous year. The depletion rate for 2007 is approximately $27 per barrel in Colombia and $10 per barrel in Argentina.

     We expect our depletion rate in Colombia to decrease as we describe in “Liquidity and Capital Resources.”

General and Administrative

		Nine Months ended
		September 30,								Increase from
		2007				2006				prior period
Cost		$	7,583,721			$	3,998,196			$	3,585,525

     The increase in general and administrative costs for the nine months ended September 30, 2007 compared to the same period in 2006, was due to the increased level of activity related to our business resulting from the acquisition of the Argosy properties in Colombia and additional properties in Argentina, Sarbanes Oxley compliance related costs and increased stock compensation due to increased grants.

Liquidated Damages

		Nine months ended
		September 30,								Increase from
		2007				2006				prior period
Liquidated damages		$	7,366,949			$	261,182			$	7,105,767

     Liquidated damages expensed in 2007 relate to liquidated damages payable to our stockholders as a result of the registration statement for 50 million units sold in the second quarter of 2006 not becoming effective within the period specified in the share registration rights agreements for those securities. We expensed a further $1,258,065 in the fourth quarter of 2006. This registration statement became effective on May 14, 2007.

     On June 27, 2007, under the terms of the Registration Rights Agreements, we obtained a sufficient number of consents from the signatories to the agreements waiving our obligation to pay in cash the accrued liquidated damages. We agreed to amend the terms of the warrants issued in the 2006 offering by reducing the exercise price of the warrants from $1.75 to $1.05 and extending the life of the warrants by one year.

     The $8.6 million liquidated damages have been recorded as expense in the consolidated statement of operations in the amounts $4,132,150 and $3,234,799 in the first and second quarters of 2007, respectively, and $1,258,065 in the fourth quarter of 2006. The amendment to the terms of the warrants has been reflected as an increase of $8.6 million in the value of warrants recorded on the consolidated balance sheet.

Unrealized Loss from Derivative Instrument

		Nine months ended
		September 30,								Increase from
		2007				2006				prior period
Cost		$	793,580				—			$	793,580

     Under the terms of the Credit Facility with Standard Bank, we were required to enter into a derivative instrument for the purpose of obtaining protection against fluctuations in the price of oil in respect of at least 50% of the June 30, 2006 Independent Reserve Evaluation Report projected aggregate net share of Colombian production after royalties for the three-year term of the Facility. In accordance with the terms of the Facility, we entered into a costless collar derivative instrument for crude oil based on WTI price, with a floor of $48.00 and a ceiling of $80.00, for a three-year period, for 400 barrels per day from March 2007 to December 2007, 300 barrels per day from January 2008 to December 2008, and 200 barrels per day from January 2009 to February 2010.

     During the nine months ended September 30, 2007, we recognized an unrealized loss on these derivative instruments as reflected in the table above.

Foreign Exchange (Gain) Loss

		Nine months ended
		September 30,								Change from
		2007				2006				prior period
(Gain) Loss		$	(91,772	)		$	277,526			$	(369,298	)

     The foreign exchange gain for the nine month period ended September 30, 2007 arose primarily from translation of local currency denominated transactions in our South American operations into US dollars against a US dollar which was significantly weaker than the same period of 2006.

Income Tax

		Nine months ended
		September 30,								Increase from
		2007				2006				prior period
Income Tax expense (recovery)		$	(1,985,918	)		$	848,200			$	2,834,118

     The income tax recovery recorded for the nine month period ended September 30, 2007 has been generated mainly by previously unrecognized Colombian tax incentives related to prior years and previously unrecognized tax assets related to Argentina loss carryforwards from prior years. This compares to a tax expense for the nine months ended September 30, 2006 as a result of net income generated by the Colombian and Argentine operations.

Capital Expenditures

     During the nine months ended September 30, 2007, we spent $10.1 million on capital projects.

     In Argentina, capital expenditures for the nine months ending September 30, 2007, were $1.0 million. We incurred costs of $0.6 million to complete the Puesto Climaco-2 sidetrack well in the Vinalar Block which was drilled in December 2006. Capital expenditures also include the acquisition and reprocessing of seismic in several areas.

     In Colombia, capital expenditures for the nine months ending September 30, 2007, were $8.9 million. We drilled the Juanambu-1 and Costayaco-1 wells for a net cost of $5.9 million. We drilled the following wells in Colombia which were dry and abandoned: Laura-1, Soyona-1 and Cachapa-1. The drilling costs for these wells were paid by our partners and the wells were drilled at no cost to Gran Tierra. We drilled the Caneyes-1 well, which was dry and abandoned, at a cost to us of $1.7 million. For the three months ended September 30, 2007, we incurred an additional $0.6 million preparing two new well locations for drilling in the Chaza Block. We incurred costs of $0.7 million on other projects in Colombia during 2007.

Results of Operations for the years ended December 31, 2006 and 2005

Revenues

     Revenues for the year ended December 31, 2006 were $12,072,913 compared to $1,059,297 for the year ended December 31, 2005. The increase in revenues is due primarily to the inclusion of a full year of Argentina operations and the acquisition of the Colombian properties in June 2006. In Argentina, the 2006 results include a full year of activities at Palmar Largo, four months at Nacatimbay, six months of activities at El Vinalar beginning July 1, 2006, and one month of activities at Chivil, commencing December 1. Revenues in 2005 reflect only the Argentina operations for a 4-month period from September 1, 2005, the date of acquisition of the Palmar Largo and Nacatimbay properties.

     In Argentina, crude oil production after 12% royalties for the year ended December 31, 2006 was 115,420 barrels, including 103,982 barrels from Palmar Largo for the full year, 7,872 barrels from El Vinalar for the period July 1 to December 31, 2006, and 3,567 barrels from Chivil for December 1 to December 31, 2006. Average daily production for these periods was 285 barrels from Palmar Largo, 43 barrels from El Vinalar and 115 barrels from Chivil. In addition, production of condensate from Nacatimbay after royalties was 363 barrels, or an average of

12 barrels per day for the period. In 2005, crude oil production after royalties of 12%, for the four-month period from September 1 (acquisition date of the Argentina properties) to December 31, 2005, was 36,011 barrels from Palmar Largo, or an average of approximately 293 barrels per day. In addition, production of condensate from Nacatimbay averaged 5 barrels per day for the period.

     In Argentina, oil sales after 12% royalties were 127,712 barrels for the year ended December 31, 2006 including 118,121 barrels from Palmar Largo for the full year, 7,644 barrels from El Vinalar for the period July 1 to December 31, 2006, and 1,947 barrels from Chivil for December 1 to December 31, 2006. Average daily sales for these periods were 324 barrels from Palmar Largo, 42 barrels from El Vinalar and 63 barrels from Chivil. In addition, sales of condensate after royalties were 363 barrels for the year. Natural gas sales at Nacatimbay, which had been shut in for most of 2005, were 41,447 thousand cubic feet, after 12% royalty, for the period, or 345 thousand cubic feet per day. Oil sales at Palmar Largo during 2005 were reduced to 25,132, or an average of 206 barrels per day, due to severe weather conditions in Northern Argentina, as extreme rainfall and poor road conditions curtailed tanker truck traffic through November and December 2005. As a result, oil inventory increased to 13,948 barrels by December 31, 2005. Natural gas sales at Nacatimbay for the period averaged 494 thousand cubic feet per day, after 12% royalty.

     In Argentina, net revenue for the year ended December 31, 2006, after deducting royalties at an average royalty rate of 12% of production revenue, and after deducting turnover taxes, was $5,033,363 for oil and $75,488 for natural gas and condensate. Net revenue for the period from incorporation on January 26, 2005 to December 31, 2005 was $1,059,297, reflecting an average royalty rate of 12% of production revenue, including $946,098 from oil at Palmar Largo and $113,199 from natural gas and condensate at Nacatimbay.

     Average sales price for Palmar Largo oil in 2006 was $34.75 per barrel (2005 — $37.80 per barrel). Average sales prices at Nacatimbay were $36.37 per barrel of condensate (2005 — $37.58 per barrel) and $1.74 per thousand cubic feet of natural gas (2005 — $1.50 per thousand cubic feet of natural gas). Oil and natural gas prices are effectively regulated in Argentina.

     In Colombia, we recorded production and results of operations beginning June 21, 2006 in conjunction with our acquisition of Argosy. We recorded no production in 2005. Production after royalties was 134,269 barrels for the period from June 21 to December 31, 2006, comprising 70,746 barrels from the Santana block and 63,523 barrels from the Guayuyaco block, representing an average production rate of 692 barrels per day for the period. Oil sales were 129,209 barrels for the period from June 21 to December 31, 2006, or 666 barrels per day on average during the period.

     In Colombia, net revenue was $6,612,190 for the year ended December 31, 2006, reflecting royalty rates of 20% for the Santana block and 8% for the Guayuyaco block. The average sales price for oil in 2006 was $52.33 per barrel.

     Interest revenue earned on our cash deposits was $351,872 for the year ended December 31, 2006 and none in 2005.

Operating Expenses

     For the year ended December 31, 2006, operating expenses were $4,233,470 compared to $395,287 in 2005, reflecting the inclusion in 2006 of a full year of Argentine operating activities at Palmar Largo, four months at Nacatimbay, six months of activities at El Vinalar beginning July 1, 2006 and one month at Chivil commencing December 1, and six months plus ten days of operations in Colombia beginning June 21, 2006.

     In Argentina, operating expenses for 2006 totaled $2,846,705 (approximating $20.37 per barrel), primarily at Palmar Largo including an inventory adjustment of $409,582 ($2.93 per barrel) due to an underlift of crude oil volumes by a partner in the Palmar Largo joint venture. As of December 31, 2006, we have accrued the impact of an agreement among the joint venture partners providing for the recovery of underlifted volumes. Operating expenses totaled $395,287 for the period from incorporation on January 26, 2005 to December 31, 2005, representing four months of operations in Argentina. This equates to an average operating cost of $8.90 per barrel of oil equivalent (natural gas conversion 20 to 1). Operating costs for 2006 have increased primarily due to workover activity at Palmar Largo. Work over costs are treated as an operating expense.

     In Colombia, operating expenses were $1,386,765 in 2006 or $10.71 per barrel for the period June 21 to December 31, 2006. We have no comparative data for 2005 because the business was acquired during 2006.

Depletion, depreciation and accretion

     Depreciation, depletion and accretion was $4,088,437 for 2006, including accretion of asset retirement obligations of $5,061, compared to $462,119 in 2005, reflecting the inclusion of a full year of operations at Palmar Largo, additional Argentina acquisitions in 2006, and the inclusion of Colombia operations in June 2006. The majority of the 2006 expense represents the depletion of oil and gas assets in Argentina and the newly acquired Colombia properties. Depreciation, depletion and accretion recorded in 2005 primarily relates to the depletion of the acquisition cost for the Argentina properties.

General and Administrative

     General and administrative costs for 2006 were $6,998,805, including staffing and other costs for our offices in Calgary, Argentina and Colombia. This represented a $4,516,735 or a 182% increase over 2005 costs. The incremental increase in general and administrative costs in 2006 was primarily due to operating fully-staffed branch offices in Colombia and Argentina, the increased level of activity related to our expansion of operations, which resulted from acquisition of the Argosy assets in Colombia and properties in Argentina, and costs related to the registration of our securities. The increase in costs was primarily in four main categories: professional services increased by $1,382,134; employee costs increased by $1,566,979; bank and debt related fees increased by $561,971; and office related costs increased by $732,199.

Liquidated Damages

     Liquidated damages of $1,527,988 recorded in 2006 relate to liquidated damages payable to our stockholders as a result of the registration statements for our securities issued in 2005 and 2006 not becoming effective within the periods specified in the share registration rights agreements for those securities. The amount expensed includes $269,923 related to 15,047,606 units issued in the fourth quarter of 2005 and first quarter of 2006 and $1,258,065 related to 50 million units sold in the second quarter of 2006. We did not have any liquidated damages in 2005. Our registration statement for our 2005 private placement became effective in February 2007, and the amount of $269,923 incurred in 2006 in connection with the late effectiveness of this registration statement is the maximum amount of liquidated damages payable in respect of these units. Our registration statement for our June 2006 private placement became effective in May 2007. In April 2007, holders of 948,853 units exercised their right to cause us to return their purchase price for their units.

Foreign Exchange Loss

     Foreign exchange loss was $370,538 for the year ended December 31, 2006 compared to a gain of $31,271 for 2005. The loss arose primarily from translation of local currency denominated transactions in our South American operations into US dollars.

Income Tax

     We recorded an income tax expense of $677,380 in 2006 compared to an income tax benefit of $29,228 in 2005. The Colombia operations generated a net income before tax of $2.4 million dollars, which resulted in a local income tax liability, offset by income tax assets arising from losses incurred in Argentina.

Net Income (Loss) Available to Common Shares

     The net loss for the year ended December 31, 2006 was $5,823,704, or $0.08 per share. This loss includes a full year of operating activities at Palmar Largo and six months plus ten days of operations in Colombia, and costs related to the share registration statements. The net loss for the period from incorporation on January 26, 2005 to December 31, 2005, was $2,219,680, equivalent to a loss of $0.16 per share. These results reflect four months of operating activity, twelve months of business activity and significant costs relating to the November 10, 2005 share exchange.

     Per share calculations for 2006 and 2005 are based on basic weighted average shares outstanding of 72,443,501 and 13,538,149, respectively.

Liquidity and Capital Resources

     As of September 30, 2007, our cash balance was $8.0 million and our current assets (including cash balance) less current liabilities was $9.3 million, compared to cash of $24.1 million and $2.2 million and current assets less current liabilities of $14.3 million and $2.8 million at December 31, 2006 and 2005, respectively. We also have a credit facility with a bank that provides for borrowing in an amount based on the present value of our petroleum reserves, up to a maximum of $50 million.

     The accounts receivable balance at September 30, 2007, increased $6.5 million to $11.6 million from $5.1 million at December 31, 2006. We reclassified a number of tax receivable balances totaling $2.2 million previously reported in accounts receivable to taxes receivable at December 31, 2006. The Argentine receivable balance decreased, as at September 30, 2007, by $1.2 million from that at December 31, 2006 due to partner payment collections for joint capital projects during 2007. The Colombian receivable balance increased by $9.0 million, as at September 30, 2007, due to increased production revenue receivable related to the new wells Costayaco-1 and Juanambu-1 and cash calls requested from joint venture partners for capital expenditures on joint projects.

     Taxes receivables, net of taxes payable, decreased by $1.1 million in the third quarter due the receipt of a $1.0 million tax refund due to the Colombian operations for 2006. We reclassified a number of tax categories totaling $2.2 million which were previously reported in accounts receivable as at December 31, 2006. Offsetting this adjustment was a net increase of $0.6 million due to increases in the Argentine VAT tax refunds due to us and in the Argentine income tax carryforward balance.

     Current liabilities decreased by $5.0 million for the nine month period ended September 30, 2007, primarily due to a reduction of $4.5 million in accrued liabilities due to the settlement of payables for Argentine property acquisition costs and drilling costs recorded in December 2006.

     During the nine months ended September 30, 2007 we reduced our cash balances by $16.1 million. We had cash outflows of $1.3 million from operating activities due to use of cash to fund operational workovers on wells in both Colombia and Argentine, increased Sarbanes Oxley related expenditures, which were offset in part by increased revenues in the third quarter of 2006 from the new wells in Colombia and changes in non-cash working capital as described above. We had cash inflows of $0.4 million inflow from financing activities as a result of the issuance of common shares upon exercise of warrants. Also, we had a $15.2 million outflow from investing activities including oil and gas property expenditures of $10.1 million relating to our drilling and other oilfield activities primarily in Colombia and changes in non-cash working capital due to investing activities as described above.

     During the year ended December 31, 2006, we increased our cash balances by $21,889,447 and funded our capital expenditures and operating expenditures from proceeds of a series of private placements of our securities. Cash outflows comprised $829,618 from operating activities and cash inflows of $69,381,827 from financing activities, offset by cash outflows of $46,672,884 for investing activities. Proceeds from private placements included $75,000,000, less issue costs of $6,303,699, from the sale of 50,000,000 units of our securities in June 2006, $610,000 from the sale of 762,500 units in the first quarter of 2006, and proceeds from the exercise of warrants to purchase common stock. However, of the amount raised, $1,280,951 was held in escrow, and the holders of those units had the right to return the units to us and receive their purchase price back under the terms of the escrow agreement because we were unable to obtain a securities laws exemption for those holders by a specified date. In April 2007, holders of those units exercised their right to cause us to return their purchase price for their units.

     During 2005, we funded the majority of our capital expenditures from funds received through three private placements of our securities. Cash inflows from financing activities were $13,206,116, offset by cash outflows of $2,277,065 from operating activities and $8,707,595 for investing activities. Proceeds from private placements included $11,428,084 from the sale of 14,285,106 units of our securities in the fourth quarter of 2005.

     Capital expenditures for the year ended December 31, 2006 were $48,394,181 and were primarily related to the Argosy purchase in Colombia, the purchase of the El Vinalar and CGC properties in Argentina, development activity at Palmar Largo, drilling activities in Colombia, and office equipment and leasehold improvements in both Calgary and Argentina. During 2005, capital expenditures for the period from incorporation on January 26, 2005 to December 31, 2005, were $8,775,327, predominantly for the acquisition cost of the Palmar Largo, Nacatimbay and Ipaguazu interests in Argentina. The purchase price for the Argentina acquisition was $7,032,714 plus post-closing adjustments of $708,955 with the remaining capital expenditures relating to our share of the cost of drilling one well at Palmar Largo.

     The following were contractual commitments at December 31, 2006, associated with debt obligations, lease obligations, and contractual commitments (in thousands):

						Payments Due by Period
						Less than
Contractual Commitment		Total				1 year				1-3 years				4-5 years
Long-Term Debt Obligations		$	—			$	—			$	—			$	—
Liquidated damages			1,527,988				1,527,988				—				—
Work Commitments - Peru			8,600,000				—				3,533,333				5,066,667
Office Leases			460,683				118,752				260,043				81,888
Office Equipment Leases			31,524				13,680				17,198				646
Vehicle			77,367				49,233				28,134				—
Housing			8,690				8,690				—				—
Total		$	10,706,252			$	1,718,343			$	3,838,709			$	5,149,201

     The minimum capital expenditure commitment for blocks 122 and 128 in Peru is $1.0 million for the initial 3-year work period. We have no other capital expenditure commitments, other than discretionary capital expenditures to be made in the normal course of operations for workover and drilling activities. As well, post-closing adjustments of $3.8 million, related to the acquisition of CGC’s interests in six properties, were paid in January 2007.

     Effective February 28, 2007, we entered into a credit facility with Standard Bank Plc. The facility has a three-year term which may be extended by agreement between the parties. The borrowing base is the present value of our petroleum reserves up to maximum of $50 million. The initial borrowing base is $7 million and the borrowing base will be re-determined semi-annually based on reserve evaluation reports. The facility includes a letter of credit sub-limit of up to $5 million. Amounts drawn down under the facility bear interest at the Eurodollar rate plus 4%. A stand-by fee of 1% per annum is charged on the un-drawn amount of the borrowing base. The facility is secured primarily by our Colombian assets. Under the terms of the facility, we are required to maintain compliance with specified financial and operating covenants. We are also required to use a derivative instrument for the purpose of obtaining protection against fluctuations in the price of oil in respect of at least 50% of the June 30, 2006 Independent Reserve Evaluation Report projected aggregate net share of Colombian production after royalties for the three-year term of the facility. No amounts have been drawn-down under the facility.

     In accordance with the terms of the credit facility with Standard Bank Plc, we entered into a costless collar derivative instrument for crude oil based on West Texas Intermediate (“WTI”) price, with a floor of $48.00 and a ceiling of $80.00, for a three-year period, for 400 barrels per day from March 2007 to December 2007, 300 barrels per day from January 2008 to December 2008, and 200 barrels per day from January 2009 to February 2010.

     During 2007, we planned to drill ten wells, conduct several workovers of existing wells, and conduct technical studies on our existing acreage.

     In Argentina, we completed the Puesto Climaco-2 side track well in the first quarter of 2007.

     In Colombia, we scheduled eight new wells for drilling in 2007, consisting of the Laura-1 exploration well in the Talora Block, the Caneyes-1 exploration well in the Rio Magdalena Block, the Soyona-1 and Cachapa-1 exploration wells in the Primavera Block, the Juanambu-1 and Floresta-1 exploration wells in the Guayuyaco Block, the Costayaco-1 exploration well in the Chaza Block, and the Piedra-1 exploration well in the Talora block. We drilled the Laura-1 in January 2007, the Caneyes-1 in February 2007, the Soyona-1 well in April and the Cachapa-1 in March 2007. The four wells were plugged and abandoned.

     We drilled successful wells in the Chaza and Guayayaco areas. We drilled the Juanambu-1 well in March 2007 and encountered hydrocarbon shows in four zones. Testing established the presence of a significant oil accumulation. We drilled and tested the Costayaco-1 well, which also indicated a significant accumulation of oil in a number of zones. Consequently, our proven reserves in Colombia have substantially increased. As a result, the depletion rate per barrel for Colombia decreased substantially in the third quarter of 2007. We put these wells on production in the third quarter of 2007 but require final government commerciality approval for Juanambu-1 production. We expect the production from these two wells to increase revenues, net of operating costs, for the remainder of the year. We expect to incur additional development costs as facilities are upgraded in both locations to facilitate production. In addition, we have initiated planning for field development as a result of the Costayaco and Juanambu discoveries. We are planning two development wells at Costayaco based on available seismic data. We commenced a new 3-D seismic data acquisition program over the Costayaco structure to optimize positioning of future drilling locations.

     In Peru, operations in 2007 included technical studies of Block 122 and Block 128 and the initiation of an aero magnetic and gravity survey over both blocks. This program commenced in the fourth quarter of 2007 and we expect it to be completed in 2008. We expect expenditures for 2007 to be $1.3 million of which $0.2 million has been spent to September 30, 2007.

     In addition to current projects, we may pursue new ventures in South America, in areas of current activity and in new regions or countries. There is no assurance additional opportunities will be available, or if we participate in additional opportunities that those opportunities will be successful. Based on projected production, prices and costs, we believe that our current operations and capital expenditure program can be maintained from cash flow from existing operations, cash on hand, and our credit facility, barring unforeseen events or a severe downturn in oil and gas prices. Should our operating cash flow decline, we would examine measures such as reducing our capital expenditure program, issuance of debt, or issuance of equity.

     Future growth and acquisitions will depend on our ability to raise additional funds through equity, warrant exercises and/or debt markets. During 2005 and 2006 we completed financing initiatives to support recent acquisition initiatives, which have also brought additional production and cash flow into our company. Increases in the borrowing base under our credit facility are dependent on our success in increasing oil and gas reserves and on future oil prices. Additional funds will be provided to us if holders of our warrants to purchase common shares decide to exercise the warrants.

     Our initiatives to raise debt or equity financing to fund capital expenditures or other acquisition and development opportunities may be affected by the market value of our common stock. If the price of our common stock declines, our ability to utilize our stock to raise capital may be negatively affected. Also, raising funds by issuing stock or other equity securities would further dilute our existing stockholders, and this dilution would be exacerbated by a decline in stock price. Any securities we issue may have rights, preferences and privileges that are senior to our existing equity securities. Borrowing money may also involve further pledging of some or all of our assets that are not currently pledged under our existing credit facility.

Off-Balance Sheet Arrangements

     As at September 30, 2007, and December 31, 2006 and 2005, we had no off-balance sheet arrangements.

Critical Accounting Estimates

Use of Estimates

     The preparation of financial statements under generally accepted accounting principles (“GAAP”) in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Our critical accounting estimates are discussed below.

Oil and Gas Accounting-Reserves Determination

     We follow the full cost method of accounting for our investment in oil and natural gas properties, as defined by the SEC, as described in note 2 to our consolidated financial statements. Full cost accounting depends on the estimated reserves we believe are recoverable from our oil and gas reserves. The process of estimating reserves is complex. It requires significant judgments and decisions based on available geological, geo-physical, engineering and economic data.

     To estimate the economically recoverable oil and natural gas reserves and related future net cash flows, we incorporate many factors and assumptions including:

	•		expected reservoir characteristics based on geological, geophysical and engineering assessments;
	•		future production rates based on historical performance and expected future operating and investment activities;
	•		future oil and gas quality differentials;
	•		assumed effects of regulation by governmental agencies; and
	•		future development and operating costs.

     We believe our assumptions are reasonable based on the information available to us at the time we prepare our estimates. However, these estimates may change substantially as additional data from ongoing development activities and production performance becomes available and as economic conditions impacting oil and gas prices and costs change.

     Management is responsible for estimating the quantities of proved oil and natural gas reserves and for preparing related disclosures. Estimates and related disclosures are prepared in accordance with SEC requirements and generally accepted industry practices in the US as prescribed by the Society of Petroleum Engineers. Reserve estimates, including the standardized measure of discounted future net cash flow and changes therein, are prepared at least annually by independent qualified reserves consultants.

     Our board of directors oversees the annual review of our oil and gas reserves and related disclosures. The Board meets with management periodically to review the reserves process, results and related disclosures and appoints and meets with the independent reserves consultants to review the scope of their work, whether they have had access to sufficient information, the nature and satisfactory resolution of any material differences of opinion, and in the case of the independent reserves consultants, their independence.

     Reserves estimates are critical to many of our accounting estimates, including:

	•		Determining whether or not an exploratory well has found economically producible reserves.
	•		Calculating our unit-of-production depletion rates. Proved reserves estimates are used to determine rates that are applied to each unit-of-production in calculating our depletion expense.
	•		Assessing, when necessary, our oil and gas assets for impairment. Estimated future cash flows are determined using proved reserves. The critical estimates used to assess impairment, including the impact of changes in reserves estimates, are discussed below.

Oil and Gas Accounting-Impairment

     We evaluate our oil and gas properties for impairment on a quarterly basis. We assess estimated discounted future cash flows to determine if properties are impaired on a cost center basis. If the 10% discounted future cash flows for a cost center are less than the carrying amount, the cost center is impaired and written down to its fair value.

     Cash flow estimates for our impairment assessments require assumptions about two primary elements — constant prices and reserves. It is difficult to determine and assess the impact of a decrease in our proved reserves on our impairment tests. The relationship between the reserves estimate and the estimated discounted cash flows is complex because of the necessary assumptions that need to be made regarding period end production rates, period end prices and costs. Under full cost accounting, we perform a ceiling test to ensure that unamortized capitalized costs in each cost centre do not exceed their fair value. We recognize an impairment loss in net earnings when the carrying amount of a cost center is not recoverable and the carrying amount of the cost center exceeds its fair value. A cost center is defined as a country. Capitalized costs, less accumulated depreciation (carrying value) are limited to the sum of: the present value of estimated future net revenues from proved oil and gas reserves, less future value of unproven properties included in the costs being amortized; less income tax effects related to the differences between the book and tax basis of the properties. If unamortized capital costs within a cost center exceed the cost center ceiling, the excess shall be charged to expense and separately disclosed during the period in which the excess occurs. As a result, we are unable to provide a reasonable sensitivity analysis of the impact that a reserves estimate decrease would have on our assessment of impairment.

     We assessed our oil and gas properties for impairment as at September 30, 2007 and December 31, 2006 and 2005 and found no impairments were required based on our assumptions. Estimates of standardized measure of our future cash flows from proved reserves were based on realized crude oil prices of $48.66 in Colombia and $35.56 to $38.57 for our Argentina properties. A future reduction in oil prices and/or quantities of proved reserves would reduce the ceiling limitation and may result in a ceiling test write-down.

Asset Retirement Obligations

     We are required to remove or remedy the effect of our activities on the environment at our present and former operating sites by dismantling and removing production facilities and remediating any damage caused. Estimating our future asset retirement obligations requires us to make estimates and judgments with respect to activities that will occur many years into the future. In addition, the ultimate financial impact of environmental laws and regulations is not always clearly known and cannot be reasonably estimated as standards evolve in the countries in which we operate.

     We record asset retirement obligations in our consolidated financial statements by discounting the present value of the estimated retirement obligations associated with our oil and gas wells and facilities and chemical plants. In arriving at amounts recorded, we make numerous assumptions and judgments with respect to ultimate settlement amounts, inflation factors, credit adjusted discount rates, timing of settlement and expected changes in legal, regulatory, environmental and political environments. The asset retirement obligations we have recorded result in an increase to the carrying cost of our property, plant and equipment. The obligations are accreted with the passage of time. A change in any one of our assumptions could impact our asset retirement obligations, our property, plant and equipment and our net income.

     It is difficult to determine the impact of a change in any one of our assumptions. As a result, we are unable to provide a reasonable sensitivity analysis of the impact a change in our assumptions would have on our financial results. We are confident, however, that our assumptions are reasonable.

Goodwill

     Goodwill represents the excess of purchase price of business combinations over the fair value of net assets acquired and we test for impairment at least annually. The impairment test requires allocating goodwill and all other assets and liabilities to assigned reporting units. We estimate the fair value of each reporting unit and compare it to the net book value of the reporting unit. If the estimated fair value of the reporting unit is less than the net book value, including goodwill, we write down the goodwill to the implied fair value of the goodwill through a charge to expense. Because quoted market prices are not available for our reporting units, we estimate the fair values of the reporting units based upon several valuation analyses, including comparable companies, comparable transactions and premiums paid. The goodwill on our financial statements was a result of the Argosy acquisition, and relates entirely to the Colombia reporting segment.

Deferred Income Taxes

     We follow the liability method of accounting for income taxes whereby we recognize future income tax assets and liabilities based on temporary differences in reported amounts for financial statement and tax purposes. We carry on business in several countries and as a result, we are subject to income taxes in numerous jurisdictions. The determination of our income tax provision is inherently complex and we are required to interpret continually changing regulations and make certain judgments. While income tax filings are subject to audits and reassessments, we believe we have made adequate provision for all income tax obligations. However, changes in facts and circumstances as a result of income tax audits, reassessments, jurisprudence and any new legislation may result in an increase or decrease in our provision for income taxes.

Warrants

     We follow the fair-value method of accounting for warrants issued to purchase our common stock. The change of $8.6 million in the fair value of warrants issued in the 2006 Offering, arising from the amendment to the terms of the warrants in connection with the settlement of the liability for liquidated damages, was determined using a Black-Scholes warrant pricing model based on a 25% volatility rate, which reflects a typical volatility rate used to value this type of financial instrument.

New Accounting Pronouncements

     Effective January 1, 2006, we adopted the SEC issued Staff Accounting Bulletin No. 108, “Considering the Effects of Prior Year Misstatements when quantifying Misstatements in Current Year Financial Statements” (“SAB 108”). SAB 108 requires companies to evaluate the materiality of identified unadjusted errors on each financial statement and related financial statement disclosure using both the rollover approach and the iron curtain approach. The rollover approach quantifies misstatements based on the effects of correcting the misstatement existing in the balance sheet at the end of the current year, irrespective of the misstatement’s year(s) of origin. Financial statements would require adjustment when either approach results in quantifying a misstatement that is material. Correcting prior year financial statements for immaterial errors would not require previously filed reports to be amended. The adoption of SAB 108 did not have a material impact on our consolidated financial statements.

     In February 2006, the FASB issued Statement 155, Accounting for Certain Hybrid Instruments, which amends Statement 133, Accounting for Derivative Instruments and Hedging Activities, and Statement 140, Accounting for Transfers and Servicing of Financial Assets and Extinguishments of Liabilities. Statement 155 permits fair value re-measurement for any hybrid financial instrument that contains an embedded derivative that otherwise would require bifurcation from its host contract in accordance with Statement 133. Statement 155 also clarifies other provisions of Statement 133 and Statement 140. This statement is effective for all financial instruments acquired or issued in fiscal years beginning after September 15, 2006 and its adoption on January 1, 2007 did not have a material impact on our results of operations or financial position.

     In July 2006, the FASB issued FIN 48 (FASB Interpretation Number) Accounting for Uncertainty in Income Taxes with respect to FAS 109 Accounting for Income Taxes regarding accounting for and disclosure of uncertain tax positions. This guidance seeks to reduce the diversity in practice associated with certain aspects of the recognition and measurement related to accounting for income taxes. FIN 48 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The interpretation requires that we recognize the impact of a tax position in the financial statements if that position is more likely than not of being sustained on audit, based on the technical merits of the position. FIN 48 also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods and disclosure. In accordance with the provisions of FIN 48, any cumulative effect resulting from the change in accounting principle is to be recorded as an adjustment to the opening balance of accumulated deficit. This interpretation is effective for fiscal years beginning after December 15, 2006 and its adoption on January 1, 2007 did not have a material impact on our consolidated financial statements and did not require us to record any amounts in the financial statements.

     In September 2006, FASB issued Statement 157, Fair Value Measurements. Statement 157 defines fair value, establishes a framework for measuring fair value under US generally accepted accounting principles and expands disclosures about fair value measurements. This statement is effective for fiscal years beginning after November 15, 2007. We do not expect the adoption of this statement will have a material impact on our results of operations or financial position.

     In December 2006, the FASB issued Staff Position (FSP) EITF 00-19-2, Accounting for Registration Payment Arrangements. FSP EITF 00-19-2 specifies that the contingent obligation to make future payments or otherwise transfer consideration under a registration payment arrangement, whether issued as a separate agreement or included as a provision of a financial instrument or other agreement, should be separately recognized and measured in accordance with FASB Statement No. 5, Accounting for Contingencies. This FSP is effective for fiscal years beginning after December 15, 2006. The Company early adopted this FSP during the year ended December 31, 2006 and recorded $1,258,065 in liquidated damages as an expense in the consolidated statement of operations and deficit and the same amount in accrued liabilities at December 31, 2006. During the six month period ended September 30, 2007 we expensed an additional amount of $7,366,949. As at September 30, 2007 we had recorded accumulated expenses for liquidated damages of $8,625,014. Pursuant to an amendment of terms of Registration Rights Payments with respect to the associated shareholder agreement, our shareholders waived the right to settle the liquidated damages in cash and in lieu agreed to an amendment of the exercise price of the warrants from $1.75 to $1.05 on June 27, 2007, and an extension of one year in the term for the warrants. The settlement of the liquidated damages is reflected as an increase to the value of the warrants included in the shareholders’ equity section of the consolidated balance sheet.

     In February 2007, the FASB issued FAS No. 159, “The Fair Value Option for Financial Assets and Financial Liabilities” (FAS 159). FAS 159 permits an entity to elect fair value as the initial and subsequent measurement attribute for many financial assets and liabilities. Entities electing the fair value option would be required to recognize changes in fair value in earnings. Entities electing the fair value option are required to distinguish on the face of the statement of financial position, the fair value of assets and liabilities for which the fair value option has been elected and similar assets and liabilities measured using another measurement attribute. FAS 159 is effective for our fiscal year 2008. The adjustment to reflect the difference between the fair value and the carrying amount would be accounted for as a cumulative-effect adjustment to retained earnings as of the date of initial adoption. We do not expect the adoption of this statement will have a material impact on our results of operations or financial position

Quarterly Financial Information

										Income Before												Basic				Diluted
										Income Tax				Income Tax								Earnings per				Earning per
		Revenues				Expenses				Provision				Provision				Net Income				Share				Share
2007
First Quarter		$	4,516,830			$	11,465,422			$	(6,948,592	)		$	298,408			$	(6,650,184	)		($	0.07	)		($	0.07	)
Second Quarter			3,749,734				9,993,111				(6,248,377	)			1,176,292				(5,072,085	)		($	0.05	)		($	0.05	)
Third Quarter			8,038,730				7,458,252				580,478				(511,219	)			1,091,697				0.01				0.01
2006
First Quarter		$	1,049,629			$	2,211,120		$		(1,161,491	)		$	57,457			$	(1,218,948	)		($	0.03	)		($	0.03	)
Second Quarter			2,089,984				2,581,393				(491,409	)			80,325				(571,734	)		($	0.01	)		($	0.01	)
Third Quarter			5,394,949				4,750,887				644,062				710,417				(66,355	)		($	0.00	)		($	0.00	)
Fourth Quarter			3,538,351				7,675,837				(4,137,486	)			(170,819	)			(3,966,667	)		($	0.04	)		($	0.04	)
		$	12,072,913			$	17,219,237			$	(5,146,324	)		$	677,380			$	(5,823,704	)		($	0.08	)		($	0.08	)
2005
First Quarter		$	—			$	496			$	(496	)		$	—			$	(496	)		$	0.00			$	0.00
Second Quarter			—				261,021				(261,021	)			—				(261,021	)		($	0.06	)		($	0.06	)
Third Quarter			349,263				626,537				(277,274	)			7,370				(284,644	)		($	0.02	)		($	0.02	)
Fourth Quarter			710,034				2,420,151				(1,710,117	)			(36,598	)			(1,673,519	)		($	0.04	)		($	0.04	)
		$	1,059,297			$	3,308,205			$	(2,248,908	)		$	(29,228	)		$	(2,219,680	)		($	0.16	)		($	0.16	)

     We made our initial acquisition of oil and gas producing and non-producing properties in Argentina in September 2005 for a total purchase price of approximately $7 million. Prior to that time we had no revenues. In June 2006, we acquired our Colombia assets for consideration of $37.5 million cash, 870,647 shares of our common stock and overriding and net profit interests in certain assets valued at $1 million. See “Business” for a description of these acquisitions.

Quantitative and Qualitative Disclosures About Market Risk

     Our principal market risk relates to oil prices. We have not hedged these risks in the past. Essentially 100% of our revenues are from oil sales at prices which are defined by contract relative to West Texas Intermediate and adjusted for transportation and quality, for each month. In Argentina, a further discount factor which is related to a tax on oil exports establishes a common pricing mechanism for all oil produced in the country, regardless of its destination.

     In accordance with the terms of the credit facility with Standard Bank Plc, which we entered into on February 28, 2007, we entered into a costless collar hedging contract for crude oil based on West Texas Intermediate (“WTI”) price, with a floor of $48.00 and a ceiling of $80.00, for a three-year period, for 400 barrels per day from March 2007 to December 2007, 300 barrels per day from January 2008 to December 2008, and 200 barrels per day from January 2009 to February 2010. At September 30, 2007, the value of this costless collar was a loss of $793,580. A hypothetical 10% increase in WTI price on September 30, 2007 would cause the loss to increase by approximately $1,862,024, and a hypothetical 10% decrease in WTI price on September 30, 2007 would cause the loss to decrease by approximately $163,276.

     We consider our exposure to interest rate risk to be immaterial. Interest rate exposures relate entirely to our investment portfolio, as we do not have short-term or long-term debt. However, if we draw down amounts under our credit facility with Standard Bank Plc, we will incur interest rate risk with respect to the amounts drawn down and outstanding. Our investment objectives are focused on preservation of principal and liquidity. By policy, we manage our exposure to market risks by limiting investments to high quality bank issuers at overnight rates. We do not hold any of these investments for trading purposes. We do not hold equity investments.

     Foreign currency risk is a factor for our company but is ameliorated to a large degree by the nature of expenditures and revenues in the countries where we operate. We have not engaged in any formal hedging activity with regard to foreign currency risk. Our reporting currency is U.S. dollars and essentially 100% of our revenues are related to the U.S. price of West Texas intermediate oil. In Colombia, we receive 75% of oil revenues in U.S. dollars and 25% in Colombian pesos at current exchange rates. The majority of our capital expenditures in Colombia are in U.S. dollars and the majority of local office costs are in local currency. As a result, the 75%/25% allocation between U.S. dollar and peso denominated revenues is approximately balanced between U.S. and peso expenditures, providing a natural currency hedge. In Argentina, reference prices for oil are in U.S. dollars and revenues are received in Argentine pesos according to current exchange rates. The majority of capital expenditures within Argentina have been in U.S. dollars with local office costs generally in pesos. While we operate in South America exclusively, the majority of our spending since our inauguration has been for acquisitions. The majority of these acquisition expenditures have been valued and paid in U.S. dollars.

BUSINESS

          On November 10, 2005, Goldstrike, Inc. (“Goldstrike”), Gran Tierra Energy Inc., a privately-held Alberta corporation which we refer to as “Gran Tierra Canada” and the holders of Gran Tierra Canada’s capital stock entered into a share purchase agreement, and Goldstrike and Gran Tierra Goldstrike Inc. (which we refer to as Goldstrike Exchange Co.) entered into an assignment agreement. In these two transactions, the holders of Gran Tierra Canada’s capital stock acquired shares of either Goldstrike common stock or exchangeable shares of Goldstrike Exchange Co., and Goldstrike Exchange Co. acquired substantially all of Gran Tierra Canada’s capital stock. Immediately following the transactions, Goldstrike Exchange Co. acquired the remaining shares of Gran Tierra Canada outstanding after the initial share exchange for shares of common stock of Gran Tierra Energy Inc. using the same exchange ratio as used in the initial exchange. This two step process was part of a single transaction whereby Gran Tierra Canada became a wholly-owned subsidiary of Goldstrike Inc. Additionally, Goldstrike changed its name to Gran Tierra Energy Inc. with the management and business operations of Gran Tierra Canada, but remains incorporated in the State of Nevada.

          In the above-described transactions between Goldstrike and the holders of Gran Tierra Canada common stock, Gran Tierra Canada shareholders were permitted to elect to receive, for each share of Gran Tierra Canada’s common stock: (1) 1.5873016 exchangeable shares of Goldstrike Exchange Co. (and ancillary rights), or (2) 1.5873016 shares of common stock of Goldstrike, or (3) a combination of Goldstrike Exchange Co. exchangeable shares and Goldstrike common stock. All of Gran Tierra Canada’s shares were, through a series of exchanges, exchanged for shares of Goldstrike and/or exchangeable shares of Goldstrike Exchange Co. Each exchangeable share of Goldstrike Exchange Co. is exchangeable into one share of our common stock and has the same voting rights as a share of our common stock.

          The share exchange between the former shareholders of Gran Tierra Canada and the former Goldstrike is treated as a recapitalization of Gran Tierra for financial accounting purposes. Accordingly, the historical financial statements of Goldstrike before the share purchase and assignment transactions will be replaced with the historical financial statements of Gran Tierra Canada before the share exchange in all future filings with the SEC.

Company Overview

          Goldstrike was incorporated in the United States in 2003. Prior to the transactions described above, Goldstrike was engaged in mineral exploration in British Colombia, Canada. Gran Tierra Canada was formed as an Alberta, Canada, corporation in early 2005. Following the above-described transactions, our operations and management are substantially the operations and management of Gran Tierra Canada prior to the transactions. The former Gran Tierra Canada was formed by an experienced management team in early 2005 with extensive experience in oil and natural gas exploration and production, including experience in most of the world’s principal petroleum producing regions. Our objective is to acquire and exploit international opportunities in oil and natural gas exploration, development and production, focusing on South America. We made our initial acquisition of oil and gas producing and non-producing properties in Argentina in September 2005 for a total purchase price of approximately $7 million. In addition, we acquired assets in Colombia and other minor interests in Argentina and Peru during 2006.

          We have not experienced any bankruptcy, receivership or similar proceedings.

Industry Introduction

          The international oil and gas industry is extremely diverse and offers distinct opportunities for companies in different countries. The fundamentals of the industry, however, are common:

o

Oil and gas reserves tend to be distributed in a pyramid pattern. The distribution of oil and gas reserves is generally depicted as a “pyramid” with the greatest number of fields being smaller fields and with very few large fields. Because of their size, the large fields are more easily located - most have already been discovered and tend to be, though are not always, the most economical to produce.

	o		Oil and gas companies tend to be distributed in a pyramid pattern. Oil and gas companies tend to be distributed in a pattern that is similar to that of oil and gas reserves. There are many small companies and few very large companies. Large companies tend to operate at the top of the resource pyramid, where rewards are larger in size but fewer in number. Smaller companies tend to operate at the base of the resource pyramid, where rewards are smaller in size but plentiful in number. Furthermore, large companies tend to divest smaller, non-core assets as they grow, and tend to acquire smaller companies that have reached a critical mass, perpetuating a cycle of growth.
	o		In a mature producing area with a mature industry, the entirety of the resource pyramid is being explored and developed by both small and large oil and gas companies. Maturity is typically a function of time and market forces. Government policy can have an important role, encouraging or discouraging the full potential of the resource base and industry.
	o		By its nature, finding and producing oil and gas is a risky business. Oil and gas deposits may be located miles below the earth’s surface. There is no guarantee, despite the sophistication of modern exploration techniques, that oil or gas will be present in a particular location without drilling. Additionally, there is no guarantee that a discovery will be commercially viable without follow up drilling, nor can there be any guarantee that such follow up drilling will be successful. There is also no guarantee that reserves once established will produce at expected rates. Furthermore, adverse political events and changing laws/regulations can threaten the economic viability of oil and gas activity, the safety and security of workers, or the reputation of a company that conducts business outside of more stable countries. The effective management of risk is integral to the oil and gas industry.
	o		The oil and gas industry is capital intensive. Investment decisions are based on long time horizons - the typical oil and gas project has a life of greater than 20 years. Economics and value are based on a long-term perspective.
	o		The production profile for a substantial majority of oil and gas reservoirs is a declining trend. Production from an oil or gas field with a fixed number of wells declines over time. That decline rate varies depending on the reservoir and well/development characteristics but in general, steepest declines are earlier in the production life of the field. Typically, production falls to a point where revenues are insufficient to cover operating costs (the project reaches its economic limit) and the field is abandoned.
	o		Production levels in a field can be maintained by more intensive drilling and/or enhancement of existing wells, and such efforts are usually made to offset the natural decline in production. A low price environment, budgetary constraints or lack of imagination can prevent companies from taking appropriate action to offset a natural decline in production. However, a shift to a high price environment can present a significant, but short term opportunity, for new operators. While production levels may be maintained for a period of time by more intensive drilling, such efforts can only be maintained for short periods of time and may not be effective. Moreover, such efforts may also be economically unfeasible and may be impermissible under rules and regulations applying to the field.

New Opportunities for Smaller Companies

          Several forces are at work in today’s energy industry which provide significant opportunities for smaller companies, like ours. The greatest opportunities tend to be in countries where resource opportunities have been undervalued or overlooked or have been considered immaterial or uneconomic by larger companies, and/or where governments are moving to realize the potential at the base of the resource pyramid by attracting smaller companies.

Company Business Plan

          Our plan is to build an international oil and gas company by operating in countries where a smaller company can proliferate. Our initial focus is in select countries in South America, currently Argentina, Colombia and Peru.

          We are applying a two-pronged approach to growth, establishing a base of production, development and exploration assets by selective acquisitions and achieving future growth through drilling. We intend to duplicate this business model across selected countries in South America. We pursue opportunities in countries with prolific petroleum systems (which in the petroleum industry are defined as geologic settings with proven petroleum source rocks, migration pathways, reservoir rocks and traps), stable legal environments and attractive royalty, taxation and other fiscal terms.

          A key to our business plan is positioning - being in the right place at the right time with the right resources. The fundamentals of this strategy are described in more detail below:

o

Position in countries that are welcoming to foreign investment, that provide attractive fiscal terms and/or offer opportunities that have been previously ignored or undervalued;

          The pace of oil and gas exploration and development in countries around the world is dictated by geology and market forces and the intermediary impact of government policy and regulation. These factors have combined today to create opportunities in South America. The initial countries of interest to Gran Tierra are Argentina - where activity has historically been dominated by the national oil company; Colombia - which has restructured its energy policies to appeal to smaller foreign companies; and Peru - which is entering a new phase of exploration activity.

o

Engage qualified, experienced and motivated professionals;

          Our management team consists of two senior international oil and gas professionals most recently with EnCana Corporation of Canada, a third member most recently with Pluspetrol in South America, a fourth member who joined our company in conjunction with the acquisition of Argosy Energy International LP in Colombia, and our fifth and newest member to join the team brings an international finance background.

          The qualifications of our board of directors complement the international experience of the management team, providing an entrepreneurial, financial and market perspective of our business by a group of individuals with experience in early stage public and private companies.

          All of our employees have previously worked with members of our management team. Qualified geophysicists, geologists and engineers are in short supply in today’s market; our management has demonstrated the ability to attract qualified professionals.

          Our success equally depends on our strong support network in the legal, accounting and finance disciplines, both at a corporate level and a local level.

o

Establish an effective local presence;

          Our management believes that establishing an effective local presence is essential for success - one that is familiar with the local operating environment, with the local oil and gas industry and with local companies and governments in order to establish and expand business in the country. We have established our office in Buenos Aires and have engaged qualified and respected local management and professionals. We intend to establish offices in all countries in which we operate. We expect our presence in Buenos Aires and recently acquired presence in Colombia to bring new and increasing opportunities.

o

Create alliances with companies that are active in areas and countries of interest, and consolidate initial land/property positions;

          Our initial acquisitions in Argentina and Colombia, and award of land in Peru, have brought us to the attention of other companies in South America, including partners, former employers and associates. We hope to build on these business relationships to bring other opportunities to us, and we expect to continue to build new relationships in the future. Such cooperation effectively multiplies our business development initiatives and develops synergies within the local industry.

o

Build a balanced portfolio of production, development, step-out and more speculative exploration opportunities;

          Our initial acquisitions in Argentina and Colombia provide a base of production to provide immediate cash flow and upside drilling potential. We are now focusing on expansion opportunities in Argentina, Colombia and Peru, which we expect will include both low and higher risk projects, with working interests that achieve an optimal balance of risk and reward.

          The most effective risk mitigation in international oil and gas is diversification, and the highest chance of success results from a diverse portfolio of independent opportunities. We are moving purposefully in that regard.

o

Assess and close opportunities expeditiously;

          We assess many oil and gas opportunities before we move to advance one; it is necessary to assess the technical, economic and strategic merits quickly in order to focus our efforts. This approach to business often provides a competitive advantage. Since inception, we evaluated more than 100 potential acquisition opportunities.

o

Do business in countries in which we are familiar with the people and assets.

          Our business model is a bringing together of peoples’ knowledge and relationships into a single entity with a single purpose. We cannot compete with the international oil and gas industry on an open tender basis. Assets and opportunities that are offered globally will receive a premium price and chance of success for any one bidder is low. Our approach is based on niche opportunities for buyer and seller, and to take advantage of our strategic relationships, established technical know-how and access to capital.

Deal Flow

          Our access to opportunities stems from a combination of experience and industry relationships of the management team and board of directors, both within and outside of South America. Deal flow is critical to growing a portfolio efficiently and effectively, to capitalize on our capabilities today, and into the future as we grow in scale and our needs evolve.

Company Financial Fundamentals

          A brief discussion of our financial fundamentals is provided below. Potential investors are encouraged to read the following information in conjunction with all of the other information provided in this filing.

          Our financial results present the former Gran Tierra Canada as the predecessor company in the share exchange with Goldstrike on November 10, 2005. The financial results of Goldstrike were eliminated on consolidation. Gran Tierra financials therefore present the activities of the former Gran Tierra Canada before the share exchange, including the initial Argentina acquisition on September 1, 2005.

          Financial results for 2006 and the first nine months of 2007 are defined by three principal events: the Argentina acquisitions on September 1, 2005, June 30, 2006 and December 1, 2006; the Colombia acquisition on June 20, 2006 and a series of private placements of our common stock associated with the acquisitions.

          Financial results for the year ended December 31, 2006 reflect a full year of operations at Palmar Largo, four months of operations at Nacatimbay, six months of operations at El Vinalar, and one month of operations at Chivil, all in Argentina, in addition to six months and ten days of operations in Colombia.

Argentina Acquisitions

          We acquired participating interests in three joint ventures on September 1, 2005. We made a formal offer to purchase the Argentina assets of Dong Won S.A (Argentinean branch of the Korean company) on May 30, 2005, that was accepted on June 22, 2005. The total acquisition cost was approximately $7 million. Our initial offer covered interests in five properties; preferential acquisition rights were exercised on two properties but the major property of interest to Gran Tierra and two minor properties became available to us. All properties are located in the Noroeste Basin region of Northern Argentina.

	o		Palmar Largo Joint Venture - Gran Tierra participation 14%, Pluspetrol (Operator) 38.15%, Repsol YPF 30%, Compañia General de Combustibles (“CGC”) 17.85%.
	o		Nacatimbay Concession - Gran Tierra participation 50%, CGC (Operator) 50%.
	o		Ipaguazu Concession - Gran Tierra participation 50%, CGC (Operator) 50%.

          Palmar Largo is the principal property, currently producing approximately 285 barrels per day of oil net to Gran Tierra (after 12% government royalties). Acquisition cost for Palmar Largo was $6,969,659 which equates to $11.24 per barrel based on net reserves of 620,400 barrels of oil, after 12% royalties. Minor volumes of natural gas and associated liquids are produced from a single well at Nacatimbay, and the Ipaguazu property is non-producing. Total acquisition cost for these two properties was $63,055.

          On June 30, 2006, we entered into a joint venture agreement with Golden Oil Corporation whereby we purchased 50% of the El Vinalar field in Argentina for $950,000. We also agreed to pay the first $2.7 million in costs for a sidetrack well related to our joint venture agreement.

          On February 15, 2006, we made an offer to acquire a portion of the interests of CGC in eight properties in Argentina. On November 2, 2006, we closed the purchase of interests in four properties for a total purchase price of $2.1 million. The assets purchased include a 93.18% participation interest in the Valle Morado block, a 100% interest in the Santa Victoria block and the remaining 50% interests in the Nacatimbay and Ipaguazu blocks.

          On December 1, 2006, we closed the purchase of interests in two other properties from CGC, including a 100% interest in the El Chivil block and a 100% participation interest in the Surubi block, each located in the Noroeste Basin of Argentina, for a total purchase price of $2.5 million. We also purchased the remaining 25% minority interest in each property from the joint venture partner for a total purchase price of $280,000.

          The total purchase price in 2006 for the acquisition of CGC’s interests in all six properties was $4.6 million. Post-closing adjustments, which reflect original values assigned to the properties, amended terms, revenues and costs from the effective date of January 1, 2006, were approximately $3.8 million which was paid in January 2007.

Colombia Acquisition

          On June 20, 2006, we acquired all of the limited partnership interests of Argosy Energy International (“Argosy”) and all of the issued and outstanding capital stock of Argosy Energy Corp. (“AEC”), a Delaware corporation and the general partner of Argosy, for consideration of $37.5 million cash, 870,647 shares of our common stock and overriding and net profit interests in certain of Argosy’s assets valued at $1 million. Argosy’s oil production averaged approximately 692 barrels per day (after royalty) during 2006. Government royalty rates are 20% and 8% for Argosy’s producing properties. Argosy’s net land position is approximately 331,468 acres.

Peru Acquisitions

          On June 8, 2006, we signed a License Contract for the Exploration and Exploitation of Hydrocarbons covering Block 122 in Peru. The license contract was approved by the government of Peru on November 3, 2006. The license contract defines a seven-year exploration term divided into four periods, each requiring a minimum work plan and financial commitment. The minimum commitment for the first work period, which is mandatory, is $0.5 million. The potential commitment over the seven-year period, at our option, is $5.0 million and includes technical studies, seismic acquisition and the drilling of one exploration well. The license contract defines an exploitation term of thirty years for commercial discoveries of oil. Block 122 is located on the eastern flank of the Maranon Basin of northern Peru, on the crest of the Iquitos Arch and covers 1.2 million acres.

          On December 12, 2006, we signed a License Contract for the Exploration and Exploitation of Hydrocarbons covering Block 128 in Peru. The license contract was approved by the government of Peru. The license contract defines a seven-year exploration term divided into four periods, each requiring a minimum work plan and financial commitment. The minimum commitment for the first work period, which is mandatory, is $0.5 million. The potential commitment over the seven-year period, at our option, is $3.6 million and includes technical studies, seismic acquisition and the drilling of one exploration well. The license contract defines an exploitation term of thirty years for commercial discoveries of oil. Block 128 is located on the eastern flank of the Maranon Basin of northern Peru, on the crest of the Iquitos Arch and covers 2.2 million acres.

Research and Development

          We have not expended any resources on pursuing research and development initiatives. We use existing technology and processes for executing our business plan.

Financing

          The initial funds for Gran Tierra Canada were raised in April and June 2005, providing approximately $1.9 million to fund our initial activities. We had no oil and gas revenue until September 1, 2005. We made a series of private placements of common shares beginning on August 31, 2005 to fund the Argentina acquisitions and to provide general working capital.

          We raised a total of approximately $12 million during the period from August 2005 to February 2006 from the issuance of approximately 15 million units consisting of one share of our common stock at $0.80 per share plus one warrant to purchase one-half share at a total price of $1.25 per share for a period of five years.

          In June 20, 2006, we completed the sale of 50,000,000 units for gross proceeds totaling $75,000,000, less issue costs of $6,306,699. Each unit consisted of one share of our common stock and a warrant to purchase one-half share of our common stock for a period of five years at an exercise price of $1.75 per whole share. During 2006 we received $1.9 million of the equity proceeds raised during the financing that began in 2005, which impacted our 2006 cash flow results.

The Share Exchange

          The share exchange between Goldstrike and the shareholders of the former Gran Tierra Canada occurred on November 10, 2005, bringing the assets, management, business operations and business plan of the former Gran Tierra Canada into the framework of the company formerly known as Goldstrike Inc., a publicly traded company.

Prior Goldstrike Business

          In connection with our share exchange between Goldstrike and the shareholders of Gran Tierra Canada, Goldstrike transferred to Dr. Yenyou Zheng all of the capital stock of Goldstrike Inc’s wholly-owned subsidiary, Leasco. Leasco was organized to hold mineral assets located in the Province of British Columbia. Those assets consist primarily of 32 mineral claims covering approximately 700 hectares. As a result of the transfer, this line of business is owned by Dr. Yenyou Zheng, through his ownership of Leasco, and we will not pursue any of those mineral claims.

Markets, Customers and Competition

          We market our own share of production in Argentina. Production from Palmar Largo is high quality oil and is transported by pipeline and truck to a nearby refinery. The purchaser of all our oil in Argentina is Refinor S.A. Minor volumes of natural gas and liquids from Nacatimbay were previously sold locally. Production at Nacatimbay was suspended on March 1, 2006. All sales are denominated in pesos but refer to reference or base prices in US dollars. Our average oil price in Argentina averaged $34.75 per barrel net of royalties during 2006 and $38.89 per barrel net of royalties during the first nine months of 2007. Sales in Argentina represented 43% of our revenues in 2006 and 36% of our revenues during the first nine months of 2007.

          The purchaser of all oil sold in Colombia is Ecopetrol, a government agency. Oil is eventually exported via the Trans-Andean pipeline. Prices are defined by a multi-year contract with Ecopetrol, with 25% of revenue received in pesos, and 75% of revenue received in US dollars. Prices averaged $52.33 per barrel net of royalties during 2006 and $58.26 per barrel net of royalties during the first nine months of 2007. Sales in Colombia represented 57% of our revenues in 2006 and 64% of our revenues during the first nine months of 2007.

          The oil and gas industry is highly competitive. We face competition from both local and international companies in acquiring properties, contracting for drilling equipment and securing trained personnel. Many of these competitors have financial and technical resources that exceed ours, and we believe that these companies have a competitive advantage in these areas. Others are smaller, allowing us to leverage our technical and financial capabilities.

Regulation

          The oil and gas industry in South America is heavily regulated. Rights and obligations with regard to exploration and production activities are explicit for each project; economics are governed by a royalty/tax regime. Various government approvals are required for property acquisitions and transfers, including, but not limited to, meeting financial and technical qualification criteria in order to be a certified as an oil and gas company in the country. Oil and gas concessions are typically granted for fixed terms with opportunity for extension.

          In Argentina, concession rights for our principal property — Palmar Largo — extend to the year 2017 and may be extended an additional ten years. Oil and gas prices in Argentina are effectively controlled and are established by decree or according to specified formulae. A tax on oil exports sets an effective cap on prices within the country; gas prices are set by statute and reflected in contract terms.

          In Colombia, the contract for the Santana area expires in 2015, the contract for the Guayuyaco area expires in 2030 and the contract for the Chaza area expires in 2027. Oil prices in Colombia are related to international market prices with pre-defined adjustments for quality and transportation. In Colombia, historically, all oil production was from concessions granted to foreign operators or undertaken by state owned Ecopetrol in contracts of association with foreign companies. Ecopetrol was formally responsible for all exploration, extraction, production, transportation, and marketing oil for export. Effective January 1, 2004, the regulatory regime in Colombia underwent a significant change with the formation of the Agencia Nacional de Hidrocarburos, or National Hydrocarbon Agency (“ANH”). The ANH is now responsible for regulating the Colombian oil industry, including managing all exploration lands not subject to a previously existing association contract.

          In Peru, state-controlled Perupetro is responsible for overall regulation and licensing of the oil and gas industry. It also negotiates oil and gas contracts with companies to explore and/or produce in Peru.

          The pace of bureaucracy in South America tends to be slow in comparison to North American standards and legal structures are less mature, but the overall business environment is supportive of foreign investment and we believe is continuing to improve. Changes in regulations or shifts in political attitudes are beyond our control and may adversely impact our business. Operations may be affected in varying degrees by government regulations with respect to restrictions on production, price controls, export controls, income taxes and environmental legislation.

Future Activity

          We plan to continue assessing production and exploration opportunities that can provide a base for growth. We are currently assessing opportunities in Argentina, Colombia, Peru and elsewhere in South America which, if consummated, could substantially increase reserves and production. We would require financing from existing cash flow, equity or debt to consummate any opportunities which may become available, depending on the scale of the opportunity.

          The totality of our business activities in Colombia, Argentina and Peru is governed by contractual arrangements with host governments including exploration and production concessions, oil sales agreements, joint venture agreements and other obligations. While it is not considered probable in these countries, these contracts may be subject to re-negotiation over time which could diminish profits compared to existing terms. A unilateral termination of contracts is considered to be highly improbable.

Geographic Information

          The following tables present information on our reportable geographic segments:

		Nine months ended September 30, 2007																Nine months ended September 30, 2006
		Corporate				Colombia				Argentina				Total				Corporate				Colombia				Argentina				Total
Revenues		$	185,965			$	10,210,297			$	5,909,032			$	16,305,294			$	193,098			$	4,077,035			$	4,284,604			$	8,554,737
Depreciation, Depletion & Accretion			87,950				4,830,133				1,631,769				6,549,852				34,295				1,164,560				1,125,303				2,324,158
Segment Income (Loss) before income tax			(13,353,674	)			2,195,484				(1,458,299	)			(12,616,489	)			(2,852,257	)			1,560,233				283,192				(1,008,832	)
Segment Capital Expenditures		$	152,136			$	8,904,228			$	1,016,748			$	10,073,112			$	107,172			$	2,086,063			$	3,818,500			$	6,011,735

		Period ended September 30, 2007																Year ended December 31, 2006
		Corporate				Colombia				Argentina				Total				Corporate				Colombia				Argentina				Total
Property, Plant & Equipment		$	451,868			$	40,348,184			$	19,490,953			$	60,291,005			$	387,682			$	36,274,088			$	20,045,618			$	56,707,388
Goodwill			—				15,005,083				—				15,005,083				—				15,005,083				—				15,005,083
Total		$	451,868			$	55,353,267			$	19,490,953			$	75,296,088			$	387,682			$	51,279,171			$	20,045,618			$	71,712,471

						Year Ended December 31, 2006													Year Ended December 31, 2005
		Corporate				Colombia				Argentina				Total					Corporate				Argentina				Total
Revenues		$	351,872			$	6,612,190			$	5,108,851			$	12,072,913				$	—			$	1,059,297			$	1,059,297
Depreciation, Depletion & Accretion			43,576				2,494,317				1,550,544				4,088,437					9,097				453,022				462,119
Segment Income (Loss) before income tax			(6,006,622	)			1,394,419				(534,121	)			(5,146,324	)				(2,136,463	)			(112,445	)			(2,248,908	)
Segment Capital Expenditures			256,482				34,053,289				14,084,410				48,394,181					131,200				8,182,008				8,313,208

						Year Ended December 31, 2006													Year Ended December 31, 2005
		Corporate				Colombia				Argentina				Total					Corporate				Argentina				Total
Property, Plant & Equipment		$	387,682			$	34,053,289			$	22,266,418			$	56,707,389				$	131,200			$	8,182,008			$	8,313,208
Goodwill			—				15,005,083				—				15,005,083					—				—				—
Total			387,682				49,058,372				22,266,418				71,712,472					131,200				8,182,008				8,313,208

Environmental Compliance

          Our activities are subject to existing laws and regulations governing environmental quality and pollution control in the foreign countries where we maintain operations. Our activities with respect to exploration, drilling and production from wells, natural gas facilities, including the operation and construction of pipelines, plants and other facilities for transporting, processing, treating or storing gas and other products, are subject to stringent environmental regulation by provincial and federal authorities in Argentina, Colombia and Peru. Risks are inherent in oil and gas exploration and production operations, and we can give no assurance that significant costs and liabilities will not be incurred in connection with environmental compliance issues. We cannot predict what effect future regulation or legislation, enforcement policies issued, and claims for damages to property, employees, other persons and the environment resulting from our operations could have. During 2006 we spent $95,373 in Colombia to comply with environmental standards around water disposal. In Argentina, we spent $10,400 on environmental monitoring and water disposal.

Employees

          At September 30, 2007, we had 121 full-time employees — eight located in the Calgary corporate office, 24 in Buenos Aires (14 office staff and 10 field personnel) and 89 in Colombia (18 staff in Bogota and 71 field personnel). None of our employees are represented by labor unions, and we consider our employee relations to be good. We had no part-time employees at September 30, 2007.

Corporate Information

          Goldstrike Inc., now known as Gran Tierra Energy Inc., was incorporated under the laws of the State of Nevada on June 6, 2003. Our principal executive offices are located at 300, 611-10th Avenue S.W., Calgary, Alberta, Canada. The telephone number at our principal executive office is (403) 265-3221.

Additional Information

          We are required to comply with the informational requirements of the Exchange Act, and accordingly, we file annual reports, quarterly reports, current reports, proxy statements and other information with the SEC. You may read or obtain a copy of these reports at the SEC’s public reference room at 100 F Street, NE, Washington, D.C. 20549. You may obtain information on the operation of the public reference room and their copy charges by calling the SEC at 1-800-SEC-0330. The SEC maintains a website that contains registration statements, reports, proxy information statements and other information regarding registrants that file electronically with the SEC. The address of the website is http://www.sec.gov.

Legal Proceedings

          Ecopetrol and Argosy Energy International L.P. (“Argosy”), the contracting parties of the Guayuyaco Association Contract, are engaged in a dispute regarding the interpretation of the procedure for allocation of oil produced and sold during the long term test of the Guayuyaco-1 and Guayuyaco-2 wells. Ecopetrol has advised Argosy of a material difference in the interpretation of the procedure established in the Clause 3.5 of Attachment-B of the Guayuyaco Association Contract. Ecopetrol interprets the contract to provide that the extend test production up to a value equal to 30% of the direct exploration costs of the wells is for Ecopetrol’s account only and serves as reimbursement of its 30% back in to the Guayuyaco discovery. Argosy’s contention is that this amount is merely the recovery of 30% of the direct exploration costs of the wells and not exclusively for benefit of Ecopetrol. The resolution of this issue is still pending agreement between the parties or determination through legal proceedings. At this time no amount has been accrued in the financial statements as it is not considered probable that a loss will be incurred. The estimated value of disputed production is $2,361,188 which possible loss is shared 50% ($1,180,594) with Solana Petroleum Exploration (Colombia) S.A. partner in the contract and 50% Argosy. Currently, no other legal claims or proceedings are pending against us (a) which claim damages in excess of 10% of our current assets, (b) which involve bankruptcy, receivership or similar proceedings, (c) which involve federal, state or local environmental laws, or (d) which involve any of our directors, officers, affiliates, or stockholders as a party with a material interest adverse to us. To our knowledge, no other proceeding against us is currently contemplated by any governmental authority.

Company Property

Offices

          We currently lease office space in Calgary, Alberta; Buenos Aires, Argentina; and Bogota, Colombia. The Calgary lease expires February 2011, and costs $6,824 per month. Our Buenos Aires, Argentina lease expires March, 2008, with lease payments of $2,000 per month. The two Bogota, Colombia leases expire in 2009 and 2007, respectively with costs of $696 and $2,326 per month. The properties are in excellent condition.

Oil and Gas Properties-Argentina

     Gran Tierra lands highlighted in yellow. Other licenses in grey. Green dots are producing oil fields, red dots are producing gas/condensate fields.

          A summary of our interests in Argentina as of December 31, 2006 is as follows:

														Oil Prod’n
		Gross								Net				Bbl/day				Oil Reserves				Lease
Noroeste Basin		Acres				WI%				Acres				(1)				MBbl (2)				Expiry				2007 Plans
Palmar Largo			365,045				14	%			51,106				285				422				2027			Ongoing production enhancements
Nacatimbay (4)			36,623				100	%			36,623				12				19				2032			Ongoing production enhancements
El Vinalar			248,340				50	%			124,170				43				466				2026			Ongoing production enhancements
Chivil			62,518				100	%			62,518				115				665				2015			Ongoing production enhancements
Surubi			90,811				100	%			90,811				—				—				2026			Drill exploration well, Proa-1, in second quarter 2008
Valle Morado			50,019				93.2	%			46,608				—				—				2033			No plans for 2007, Test production capability 2008
Ipaguazu			43,268				100	%			43,268				—				323				2026			Ongoing production enhancements
Santa Victoria			1,033,749				100	%			1,033,749				—				—				(3	)		Exploration opportunities are being evaluated
Total			1,930,373								1,488,853				455				1,895

(1)		Oil production is based on the average December 2006 production rate.
(2)		Oil reserves are proved reserves reported in thousands of barrels, net of royalties.
(3)		Expires in May 2008. Term is extended by 25 years if a discovery is made.
(4)		We produce natural gas in the Nacatimbay area. Natural gas production in December 2006 was 440 thousand cubic feet per day and total proved reserves at December 31, 2006 were 1,465 million cubic feet.

Palmar Largo

          The Palmar Largo joint venture block encompasses 365,045 acres. This asset is comprised of several producing oil fields in the Noroeste Basin of northern Argentina. We own a 14% working interest in the Palmar Largo joint venture asset. Approximately 41.8 million barrels of oil (gross before royalties) have been recovered from the area since 1984. A total of 14 gross wells are currently producing. Our share of remaining proved reserves as of December 31, 2006 is 422,000 barrels (net after 12% royalties) according to an independent reserve assessment. The oil quality ranges from 39 to 47 degrees API.

          During the first half of 2007, our 14% share of oil production averaged 275 barrels per day, net of royalties. During 2006 and 2005, our share of oil production averaged 285 and 293 barrels per day, net of royalties, respectively. The Palmar Largo asset provides us with a reliable stream of cash flow to finance further exploration and development initiatives in Argentina. Our work program for 2007 involves optimization of well performance and expenses to maximize net revenues from the property.

          We purchased the assets of Palmar Largo from Dong Won Corporation in September 2005. In the first quarter of 2006 the joint venture partners drilled and completed the Ramon Lista 1001 well, of which we hold a 14% working interest. The recent history of the property includes the following activities:

	•		The joint venture partners at Palmar Largo conducted a 3-D seismic survey over a portion of the area in 2003 and identified several exploration prospects.
	•		An exploration well was drilled in late 2005 but did not indicate commercial quantities of oil. A portion of the drilling costs for this well was factored into our purchase price for Palmar Largo.
	•		Drilling on the Ramon Lista-1001 well was completed in December 2005. Production from the well began in early February 2006 at 299 barrels per day (gross after 12% royalty) or 42 barrels per day net to us. No additional wells were drilled in the area during 2006.

          The Palmar Largo block rights expire in 2017 but provide for a ten-year extension. We do not have any outstanding work commitments. At expiry of the block rights, ownership of the producing assets will revert to the provincial government.

Nacatimbay

          We acquired a 100% working interest in the Nacatimbay area through two transactions. We purchased a 50% working interest from Dong Won Corporation in September 2005. We purchased the remaining 50% working interest from CGC in November 2006. Production from the Nacatimbay oil, gas and condensate field began in 1996. Three wells were drilled and one well produced natural gas and condensate for 120 days during 2006. The well has been shut in since early 2007.

           We continued to optimize production in this field during 2007 and explore opportunities to re-enter the Nacatimbay 1001 and 1002 wells.

          The Nacatimbay block rights expire in 2022 with a provision for a ten year extension if a discovery is made. We do not have any outstanding work commitments. At expiry of the block rights, ownership of the producing assets will revert to the provincial government.

Ipaguazu

          We acquired a 100% working interest in the Ipaguazu area through two transactions. We purchased a 50% working interest from Dong Won Corporation in September 2005. We purchased the remaining 50% working interest from CGC in November 2006. Ipaguazu is located in the Noroeste Basin in northern Argentina. The oil and gas field was discovered in 1981 and produced approximately 100 thousand barrels of oil and 400 million cubic feet of natural gas until 2003. The Ipaguazu block covers 43,268 acres and has not been fully appraised, leaving scope for both reactivation and exploration in the future. Currently we are evaluating a workover on the Ipaguazu-1 well.

          The Ipaguazu block rights expire in 2016 with a ten year extension if a discovery is made. We do not have any outstanding work commitments. At expiry of the block rights, ownership of the producing assets will revert to the provincial government.

El Vinalar

          We entered into an agreement with Golden Oil Corporation to acquire a 50% working interest in the El Vinalar Block located in the Noroeste Basin, effective June 2006. This acquisition added a significant new land position and approximately 43 barrels of daily oil production from 1.5 net wells, net before royalties, to our asset base in Argentina. El Vinalar covers 248,340 acres and contains a portfolio of exploration leads and oil field enhancement opportunities.

          A sidetrack of EVN-1 well was successfully completed in December 2006, and began producing in January 2007. Our 50% share of production, after royalties, averaged 242 barrels per day for the first nine months of 2007.

          The El Vinalar rights expire in 2016 with a ten year extension if a discovery is made. We do not have any outstanding work commitments. At expiry of the block rights, ownership of the producing assets will revert to the provincial government.

Chivil, Surubi, Valle Morado, Santa Victoria

          We purchased working interests in four additional properties from CGC in November and December 2006. These properties add to our existing portfolio of exploration and development opportunities and expand our production base in Argentina. Farm-in partners are being sought to participate in the 2008 drilling program for the Surubi property.

Additional information on the Chivil, Surubi, Valle Morado and Santa Victoria fields follows:

	§		The Chivil field was discovered in 1987. Three wells were drilled; two remain in production and have averaged 100 barrels per day, net of royalties, for the first nine months of 2007. The field has produced 1.5 million barrels to date.
	§		Valle Morado was first drilled in 1989. Rights to the area were purchased by Shell in 1998, who subsequently completed a 3-D seismic program over the field and constructed a gas plant and pipeline infrastructure. Production began in 1999 from a single well, and was shut-in in 2001 due to water incursion. We are evaluating opportunities to re-establish production from the field in 2008.
	§		Surubi and Santa Victoria are exploration properties and have no production history.

Reserves Summary-Argentina

Crude Oil — Estimated Reserves

Net to Gran Tierra, after Royalty, at December 31,

		Oil 2005													Oil 2006 (1)
		(thousand barrels)													(thousand barrels)
		Proved				Proved				Total					Proved				Proved
		Developed				Undeveloped				Proved					Developed				Undeveloped				Total Proved
Palmar Largo			462				119				581					404				18				422
Ipaguazu			—				—				—					323				—				323
Nacatimbay(2)			2				—				2					19				—				19
El Vinalar			—				—				—					191				275				466
Chivil			—				—				—					476				189				665
Surubi			—				—				—					—				—				—
Valle Morado			—				—				—					—				—				—
Santa Victoria			—				—				—					—				—				—
TOTAL			464				119				583					1,413				482				1,895

(1)		Reserves certified by Gaffney, Cline and Associates, as of December 31, 2006.
(2)		Includes natural gas liquids

Natural Gas — Estimated Reserves
Net to Gran Tierra, after Royalty, at December 31,

		Natural Gas 2005													Natural Gas 2006 (1)
		(million cubic feet)													(million cubic feet)
		Proved				Proved									Proved				Proved
		Developed				Undeveloped				Total Proved					Developed				Undeveloped				Total Proved
Palmar Largo			—				—										—				—				—
Ipaguazu			—				—					—					—				—				—
Nacatimbay			24.5				—					24.5					1,465				—				1,465
El Vinalar			—				—					—					—				—				—
Chivil			—				—					—					—				—				—
Surubi			—				—					—					—				—				—
Valle Morado			—				—					—					—				—				—
Santa Victoria			—				—					—					—				—				—
TOTAL			24.5				—					24.5					1,465				—				1,465

(1)		Reserves certified by Gaffney, Cline and Associates, as of December 31, 2006.

No estimates of proved reserves have been filed with any other Federal authority or agency since January 1, 2006.

Production Profile – Argentina

Net of royalties			Oil Production (Bbls)									Oil Price ($/Bbl)									Oil Production Costs ($/Bbl)									Net Revenue ($/Bbl)
			2005				2006					2005				2006					2005				2006					2005				2006
Palmar Largo				106,945				103,982				$	37.80			$	34.75				$	8.90			$	21.42				$	28.90			$	13.33
Nacatimbay				1,825				—				$	37.80			$	—				$	8.90			$	—				$	28.90			$	—
El Vinalar				—				7,872					—			$	53.16				$	—			$	18.49				$	—			$	34.67
Chivil				—				3,567					—			$	51.57				$	—			$	18.49				$	—			$	33.08
TOTAL				108,770				115,421				$	37.80			$	36.53				$	8.90			$	21.13				$	28.90			$	15.40
Net of royalties			Gas Production (Mcf)									Gas Price ($/Mcf)									Gas Production Costs ($/Mcf)									Net Revenue ($/Mcf)
			2005				2006					2005				2006					2005				2006					2005				2006
Palmar Largo (1)				—				156,471				$	—			$	—				$	—			$	—				$	—			$	—
Nacatimbay				180,310				41,447				$	1.50			$	1.74				$	0.45			$	0.54				$	1.06			$	1.20
El Vinalar				—				—				$	—			$	—				$	—			$	—				$	—			$	—
Chivil				—				—				$	—			$	—				$	—			$	—				$	—			$	—
TOTAL				180,310				197,918				$	1.50			$	1.74				$	0.45			$	0.54				$	1.06			$	1.20

(1)		Production of natural gas at Palmar Largo is not sold. It is used as fuel for power and gas lift for production.

Acreage — Argentina

GRAN TIERRA, December 31,
Crude Oil			Developed Gross (1)									Developed Net (2)									Undeveloped Gross (1)									Undeveloped Net (2)
			2005				2006					2005				2006					2005				2006					2005				2006
Palmar Largo				301,700				365,045					42,238				51,106					—				—					—				—
Ipaguazu				43,200				43,268					21,600				43,268					—				—					—				—
Nacatimbay				36,600				36,623					18,300				36,623					—				—					—				—
El Vinalar				—				248,340					—				124,170					—				—					—				—
Chivil				—				62,518					—				62,518					—				—					—				—
Surubi				—				—					—				—					—				90,811					—				90,811
Valle Morado				—				—					—				—					—				50,019					—				46,608
Santa Victoria				—				—					—				—					—				1,033,749					—				1,033,749
TOTAL				381,500				755,794					82,138				317,685					—				1,174,579					—				1,171,168

(1)		Gross represents the total acreage at each property.
(2)		Net represents our interest in the total acreage at each property.

Productive Wells - Argentina

		GRAN TIERRA, December 31,
(Number of wells)			Oil Productive -Net									Oil Productive -Gross									Gas Productive -Net									Gas Productive -Gross
			2005				2006					2005				2006					2005				2006					2005				2006
Palmar Largo				2.2				2.0					16				14					—				—					—				—
Ipaguazu				—				—					—				—					—				—					—				—
Nacatimbay				—				—					—				—					1				1					1				1
El Vinalar				—				1.5					—				3					—				—					—				—
Chivil				—				2.0					—				2					—				—					—				—
Surubi				—				—					—				—					—				—					—				—
Valle Morado				—				—					—				—					—				—					—				—
Santa Victoria				—				—					—				—					—				—					—				—
TOTAL				2.2				5.5					16				19					1				1					1				1

Drilling Activity - Argentina

			Productive - Gross (1)									Productive - Net (2)									Dry – Gross (1)								Dry – Net (2)
			2005				2006					2005				2006					2005				2006				2005				2006
Exploration				—				—					—				—					—				—				—				—
Development				1				1					0.14				0.14					—				—				—				—
TOTAL				1				1					0.14				0.14					—				—				—				—

(1)		Represents the total number of wells at which there is drilling activity.
(2)		Represents Gran Tierra’s interest in the total number of wells at which there is drilling activity.