Southwestern Energy Company, an independent energy company, engages in the exploration, development, and production of natural gas, oil, and natural gas liquids (NGLs) in the United States. It operates through Exploration and Production, and Marketing segments. The company focuses on the development of unconventional natural gas reservoirs located in Pennsylvania and West Virginia. As of December 31, 2019, it had approximately 173,994 net acres in Northeast Appalachia; and approximately 287,693 net acres in Southwest Appalachia. The company's estimated proved natural gas, oil, and NGLs reserves comprise 12,721 billion cubic feet of natural gas equivalent (Bcfe); and 929 Bcfe of proved undeveloped reserves. It also engages in marketing of natural gas, oil, and NGLs. It serves energy companies, utilities, and industrial purchasers of natural gas. Southwestern Energy Company was founded in 1929 and is headquartered in Spring, Texas.