The development of the hydrocarbon-rich area of northern West Virginia is critical to the growth of MarkWest’s Liberty segment and the expansion of its processing complexes in the Marcellus Shale. By the end of 2014, MarkWest will have over 2.5 Bcf/d of processing capacity in Pennsylvania and West Virginia and the ability to continue offering its Marcellus producer customers like Antero premier midstream solutions. The natural gas production and associated NGL production in MarkWest’s Liberty segment are supported by largely fee-based, long-term agreements.“Antero is a proven and highly successful operator in unconventional resource plays and we are very pleased to support their growth in the Marcellus Shale,” said Frank Semple, Chairman, President and Chief Executive Officer of MarkWest. “The commencement of operations at our Sherwood complex underscores our ongoing commitment to lead the development of solutions in the liquids-rich areas of the Marcellus and Utica Shales.” “The start-up of Sherwood I is an exciting event for Antero as it represents the first step in realizing the value of our large Marcellus rich gas resource base in West Virginia,” said Paul Rady, Chairman and Chief Executive Officer of Antero. “We have enjoyed a long relationship with Frank Semple and his team dating back to the Woodford Shale Play, so we have a lot of confidence in partnering with MarkWest to bring rich gas processing and marketing capability to the Marcellus in West Virginia.” About MarkWest Energy Partners, L.P. MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, transportation, and processing of natural gas; the transportation, fractionation, marketing, and storage of natural gas liquids; and the gathering and transportation of crude oil. MarkWest has extensive natural gas gathering, processing, and transmission operations in the southwest, Gulf Coast, and northeast regions of the United States, including the Marcellus Shale, and is the largest natural gas processor and fractionator in the Appalachian region.