Riverstone Holdings Makes Additional Investment in Three Rivers Natural Resource Holdings LLC to Significantly Expand its Position in the Permian Basin

Austin, TX and New York, NY (Jan. 20, 2011) – The Riverstone/Carlyle Global Energy and Power Funds, a group of energy-focused private equity funds managed by Riverstone Holdings LLC (“Riverstone”), announced today that an additional investment was made in Three Rivers Natural Resource Holdings LLC (“Three Rivers”), a private upstream oil & gas company based in Austin, Texas. Separately, Three Rivers acquired certain assets located in the Permian Basin of West Texas and Southeast New Mexico from Samson Resources and its affiliates (“Samson”).

Combining the most recent acquisition with the transaction announced in April 2010, Three Rivers has an ownership interest in more than 1,400 wells, with daily production of approximately 7,400 barrels of oil equivalent per day, and proven reserves of 86 million barrels of oil equivalent. Three Rivers expects 2011 full year revenue to be approximately $150 million.

Mike Wichterich, CEO of Three Rivers said, “Riverstone’s demonstration of confidence in our team and business plan represents an exciting opportunity to grow our operations throughout the Permian. Without their experience and knowledge of the E&P business, our transaction with Samson would not have been possible.”

Pierre Lapeyre and David Leuschen, Co-Founders of Riverstone, added, “We are excited to support Three Rivers in achieving this milestone in their business plan. We look forward to their continued growth.”

About Three Rivers
Three Rivers is a private, upstream oil and gas company headquartered in Austin, Texas. The Company is focused on the acquisition, development and exploitation of oil and natural gas reserves in the Permian Basin in West Texas and Southeast New Mexico.

About Riverstone Holdings LLC
Riverstone Holdings LLC, an energy and power-focused private equity firm founded in 2000, has approximately $17 billion under management across six investment funds, including the world’s largest renewable energy fund. Riverstone conducts buyout and growth capital investments in the midstream, exploration & production, oilfield services, power and renewable sectors of the energy industry. With offices in New York, London and Houston, the firm has committed approximately $15.6 billion to 75 investments in North America, Latin America, Europe and Asia. For more information, visit www.riverstonellc.com.

Contact:
For Three Rivers
Gabe Ellisor
Chief Financial Officer
512-600-3181