Gastar Exploration Inc., an independent energy company, engages in the exploration, development and production of oil, condensate, natural gas, and natural gas liquids in the United States. Its principal activities include the identification, acquisition, exploration, and development of oil and natural gas properties on unconventional reserves, such as shale resource plays. The company holds interests in the oil and natural gas-rich reservoirs, including the Oswego limestone, Meramec, and Osage bench formations within the Mississippi Lime; and the Woodford shale formations. As of February 28, 2018, its principal assets included the STACK play covering approximately 67,800 net acres located in the Mid-Continent area of the United States. The company was formerly known as Gastar Exploration Ltd. and changed its name to Gastar Exploration Inc. in January 2014. Gastar Exploration Inc. is based in Houston, Texas.