Southwestern Energy Co. is an independent energy company, which engages in the natural gas and oil exploration, development and production. It also focuses on creating and capturing additional value through its natural gas gathering and marketing businesses. The company operates its business through two segments: Exploration and Production & Midstream Services. The Exploration and Production segment engages in the business of exploration for and production of natural gas and oil, with current operations principally focused within the United States on the development of two unconventional natural gas reservoirs located in Arkansas and Pennsylvania. Its operations in Arkansas are primarily focused on an unconventional natural gas reservoir known as the Fayetteville Shale, and its operations in Pennsylvania are focused on the unconventional natural gas reservoir known as the Marcellus Shale. The Midstream Services segment engage in natural gas gathering activities in Arkansas, Texas and Pennsylvania through its gathering subsidiaries, DeSoto Gathering Co, L.L.C. and Angelina Gathering Co, L.L.C. DeSoto Gathering and Angelina Gathering primarily support its E&P operations and generate revenue from fees associated with gathering of natural gas. Southwestern Energy was founded on July 2, 1929 and is headquartered in Spring, TX.