Gran Tierra Energy Inc. announced the results of the hydrocarbon appraisal of a recent exploration well on its concession block in Colombia. The well was drilled on the Chaza Block in the Putumayo Basin.

Gran Tierra Energy Inc. drilled the Moqueta-1 exploration well earlier in the year and encountered hydrocarbons at approximately 4,000 feet. The company found 53 feet of net pay in the Caballos formation, and 55 feet of net pay in the Villeta T Sandstone formation.

Gran Tierra Energy Inc. said that the Caballos had both oil and natural gas zones present, while the Villeta T Sandstone had only natural gas. The company tested a 39 foot section of the Caballos, and produced 349 barrels of oil per day. A 12 foot section of the Villeta T Sandstone was also tested and produced 13 million cubic feet of natural gas per day.

Gran Tierra Energy Inc. has allocated capital to build an eight kilometer pipeline from the Moqueta-1 exploration well to existing infrastructure at Costayaco, where the company will start production in early 2011.

Gran Tierra Energy Inc. is in the early planning stages of the Moqueta-2 and Moqueta-3 wells. The company has a 100% working interest in the Chaza Block, and also has an interest in the nearby Santana and Guayuyaco Blocks.

For more information on the company, go to www.grantierra.com