Carrie Endorf

Callon Petroleum Co. engages in the exploration, development, acquisition, and production of oil and natural gas properties in the United States. It focuses on unconventional oil and natural gas reserves in the Permian Basin. The company was founded by Sim C. Callon and John S. Callon in 1950 and is headquartered in Houston, TX.

Pioneer Natural Resources Co. operates as an independent oil and gas exploration and production company. The firm engages in hydrocarbon exploration in the Cline Shale. It focuses on the operation of the Permian Basin, Eagle Ford Shale, Rockies, and West Panhandle projects. The company was founded by Scott Douglas Sheffield on April 2, 1997, and is headquartered in Irving, TX.

Parsley Energy, Inc. is an oil and natural gas company, which engages in the acquisition, development and exploitation of unconventional oil and natural gas reserves. Its portfolio includes Midland and Southern Delaware basin. The company was founded by Bryan Sheffield, Mike Hinson, and Paul Treadwell in 2008 and is headquartered in Austin, TX.