David Lee Young

MarkWest Energy Partners LP engages in the business of gathering, processing and transportation of natural gas; the transportation, fractionation, storage and marketing of natural gas liquids; and the gathering and transportation of crude oil. It operates through four segments: Marcellus, Utica, Northeast and Southwest. The Southwest segment includes the operations of processing facilities in Corpus Christi, Texas. The Northeast segment assets include the Kenova, Boldman, Cobb, Kermit and the Langley natural gas processing complexes, NGL pipeline and Siloam NGL fractionation facility. The Marcellus segment includes gathering, processing and fractionation infrastructure in the liquids-rich area of the Marcellus Shale The Utica segment provides fractionation services. The company was founded in January 2002 and is headquartered in Denver, CO.

Part of Marathon Petroleum Corp., MarkWest Energy GP LLC is a company that provides oil and gas field services not elsewhere classified. The company is based in Englewood, CO. The company was founded by John C. Mollenkopf.

Wiltel Communications Group, Inc. provides customized communications solutions to enterprises, and federal government. The company was founded by Robert D. Williams and is headquartered in Tulsa, OK.

Texas Gas Transmission LLC provides oil and gas transmission and storage services, Its services include business development, transportation and storage and marketing and optimization services. The company was established in 1948 and is headquartered in Owensboro, KY.