10 January 2007

Gran Tierra Continues Well Testing in Argentina and Initiates Drilling Operations in Colombia; Re-establishes Gas Production in Argentina

CALGARY, Alberta, January 10, 2007, Gran Tierra Energy Inc. (OTC Bulletin Board: GTRE.OB) today announced that the Company is continuing well testing operations in Argentina and has initiated drilling operations in Colombia. In addition, gas production has been re-established at the previously shut-in Nacatimbay Field in the Nacatimbay block of Argentina.

Testing is continuing on the Puesto Climaco-2 sidetrack in the Vinalar block in Argentina. Gran Tierra holds a 50% working interest in this block. A second short sidetrack was required when logging tools were stuck in the hole during initial reservoir evaluation in late December, 2006. The new hole has now been cased and logged, with perforations and testing to take place in the coming days. Production facilities associated with the Puesto Climaco field are in place and ready to accommodate additional production from the Puesto Climaco-2 sidetrack immediately.

Also in Argentina, a workover rig has arrived at the Ipaguazu field to recomplete the IPX-1 well and re-establish production from this shut-in field. Gran Tierra holds a 100% working interest in the Ipaguazu block. These workover operations are continuing. Production at the Nacatimbay Field in the near-by Nacatimbay Block, where Gran Tierra Energy has a 100% working interest, has been re-established following facilities upgrade activity. This previously shut-in field is now producing approximately 570 thousand cubic feet of gas per day, plus associated condensate and natural gas liquids.

In Colombia, drilling was initiated on the Laura-1 prospect in the Talora block in the Middle Magdalena Basin on December 27. Gran Tierra has a 20% carried working interest in this block. Drilling is continuing and will be completed this month. Following the completion of Laura-1, the same drilling rig will mobilize to drill the Caneyes-1 prospect in the adjacent Rio Magdalena block in Colombia in late January, 2007. Construction of the drilling location is underway. Gran Tierra currently holds a 100% working interest in this contact area, which is subject to a 30% back-in provision by Ecopetrol, the government petroleum agency, in the event of commerciality.

Mobilization is continuing with another rig to the Primavera Block in the Llanos Basin to drill two wells, Capibara-1 and Cachapa-1, in February, 2007. Gran Tierra holds a 15% interest in this block. A third drilling rig is currently being rigged up to drill the Juanambu-1 prospect in the Guayuyaco block in the Putumayo Basin of Colombia. Drilling is scheduled to commence on January 15, 2007. Gran Tierra’s interest in this block is 35% after the Ecopetrol back-in. The rig is planned to be moved to the adjacent Chaza block to drill the Naboyaco-1 prospect immediately after drilling Juanambu-1. Gran Tierra Energy holds a 50% working interest in the Chaza contact area.

Dana Coffield, President and Chief Executive Officer of Gran Tierra, stated “Our simultaneous drilling operations in our two primary operational arenas, Argentina and Colombia, are now fully engaged, with the intent to add material new reserves and production through the drill bit in the first half of 2007.”

About Gran Tierra Energy Inc.
Gran Tierra Energy, Inc. is an international oil and gas exploration and production company, headquartered in Calgary, Canada, incorporated and traded in the United States and operating in South America. The Company holds interests in producing and prospective properties in Argentina, Colombia and Peru. To date, the Company has pursued a strategy that focuses on establishing a portfolio of producing properties, development and exploration opportunities, through selective acquisitions, to provide a base for future growth. Additional information concerning Gran Tierra is available at www.grantierra.com. Investor inquiries may be directed to info@grantierra.com or 1-800-916-GTRE (4873).

Forward Looking Statements
This press release contains ‘forward-looking statements’ within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, including without limitation those statements regarding the Company’s ability to exploit oil and gas exploration opportunities. 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. Although the forward-looking statements in this release reflect the good faith judgment of management, forward-looking statements are inherently subject to known and unknown risks and uncertainties that may cause actual results to be materially different from those discussed in these forward-looking statements including, but not limited to, our ability to complete the Company’s drilling program for 2007, our ability to discover reserves that may be extracted on a commercially viable basis, difficulties inherent in estimating oil and gas reserves, intense competition in the oil and gas industry, environmental risks, regulatory changes and general economic conditions including the price of oil and gas. Readers are urged not to place undue reliance on these forward-looking statements, which speak only as of the date of this release. 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 release, 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 the our reports filed with the Securities and Exchange Commission, including those risks set forth in the Company’s Annual Report on Form 10-KSB filed on March 10, 2006, as amended, 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. We undertake no obligation to update these forward looking statements.