Southwestern Energy Company explores, develops, and produces natural gas and oil in the United States. The company operates in two segments, Exploration, Development and Production; and Midstream Services. It focuses on the Fayetteville Shale, an unconventional natural gas reservoir covering approximately 888,161 net acres in Arkansas; and the Marcellus Shale, an unconventional natural gas reservoir covering approximately 266,073 net acres in northeast Pennsylvania. The company also engages in the exploration and production activities in Colorado, Louisiana, and Texas; and in the Arkoma Basin in Arkansas and Oklahoma. In addition, it is involved in the gathering, marketing, and transporting natural gas, and oil and natural gas liquids. As of December 31, 2014, the company had a pipeline of 2,017 miles in Arkansas, 105 miles in Pennsylvania, 25 miles in Texas, and 16 miles in Louisiana in its gathering systems. Southwestern Energy Company was formerly known as Arkansas Western Gas Company and changed its name to Southwestern Energy Company in October, 1979. The company was founded in 1929 and is based in Spring, Texas.