Gastar Exploration is a holding company. Through its subsidiaries, Co. is an independent energy company engaged in the exploration, development and production of oil, condensate, natural gas and natural gas liquids. Co.'s 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. As of Dec 31 2016, Co.'s estimated proved reserves consisted of 13.8 million barrels of condensate and oil, 37.85 billion cubic feet of natural gas, and 5.5 million barrels of natural gas liquids.