Mark A. Stevens

XTO Energy Inc. operates as a domestic energy producer engaged in the acquisition, development, and discovery of oil and natural gas properties in the United States. It specializes in the development of tight gas, shale gas, coal bed methane, and unconventional oil resources. The company was founded by Steve Palko, Bob Simpson and Jon Brumley in 1986 and is headquartered in Spring, TX.

Athlon Energy, Inc. operates as an independent exploration and production company. The firm engages in the acquisition, development and exploitation of unconventional oil and liquids-rich natural gas reserves in the Permian Basin. The company was founded in 2010 and is headquartered in Fort Worth, TX.