Gastar Exploration, Inc. is an independent energy company. The Company is engaged in the exploration, development and production of oil, condensate, natural gas and natural gas liquids (NGLs) in the United States. Its principal business activities include the identification, acquisition, and subsequent exploration and development of oil and natural gas properties with a focus on unconventional reserves, such as shale resource plays. Its properties consist primarily of oil and natural gas leases in mid-continent area of the United States in Oklahoma; Marcellus Shale in the Appalachian Basin in West Virginia and central and southwestern Pennsylvania, and Utica Shale in the Appalachian Basin in West Virginia. In Oklahoma, the Company develops the primarily oil-bearing reservoirs of the Hunton Limestone horizontal oil play. In West Virginia, the Company develops liquids-rich natural gas in the Marcellus Shale.