P. engages in the gathering, processing, and transmission of natural gas; the transportation, fractionation, and storage of natural gas liquids (NGL) products; and the gathering and transportation of crude oil in the United States.
It owns 5 natural gas processing plants, 136 miles of NGL pipeline, an NGL fractionation plant, and a 11 million-gallon underground NGL storage facility in the Appalachian basin; an aggregate of 302 miles of natural gas gathering pipelines in 19 gathering systems in Texas, Oklahoma, Louisiana, Mississippi, and New Mexico, as well as a gas processing plant and 4 Texas intrastate gas transmission pipelines that transmit natural gas to power plants, municipalities, and other industrial end users; and a 90 mile gas-gathering pipeline, a natural gas processing plant, and approximately 250 miles of an intrastate crude gathering pipeline in Michigan.
The company is not subject to income taxes.
MarkWest Energy Partners was formed in January 2002 and is based in Englewood, Colorado.
The company acquired of Carthage gathering system and gas processing assets of American Central East Texas Gas Company, L.
P. in July 2004.

