Britt Pence

Vanguard Natural Resources LLC is an oil and natural gas exploration company, which focuses on the acquisition and development of mature long-lived natural gas and oil properties. Its properties are located in the Appalachian Basin in Kentucky and Tennessee; the Permian Basin in West Texas and New Mexico; and the Big Horn Basin in Wyoming and Montana. The company was founded in October 2006 and is headquartered in Houston, TX.

Anadarko Petroleum Corp. is an independent exploration and production company. It operates through the following segments: Exploration and Production; WES Midstream; and Other Midstream. The Exploration and Production segment focuses on the exploration, development, production, and sale of oil and natural gas. The WES Midstream and Other Midstream segment consists of gathering, compressing, treating, processing, and transporting of natural gas; gathering, stabilizing, and transporting of oil and natural gas liquids. The company was founded in 1959 and is headquartered in The Woodlands, TX.

Part of Pioneer Natural Resources Co., Greenhill Petroleum Corp explores for and produces oil. Greenhill Petroleum was acquired by Mesa, Inc. from Alumina Ltd. on April 17, 1997 for $267 million.

Part of Exxon Mobil Corp., Encore Energy Partners GP LLC is a company based in Dallas, TX. Scott W. Smith has been the CEO of the company since 2010.