Pioneer Natural Resources Company operates as an independent oil and gas exploration and production company in the United States. The company produces and sells oil, natural gas liquids (NGL), and gas. Its proved reserves are primarily located in the Spraberry field in the Permian Basin area, the Hugoton and West Panhandle fields in the Mid-Continent area, and the Raton field in the Rocky Mountains area; and development and exploration activities are located in the Spraberry field, Raton field, Eagle Ford Shale play, Barnett Shale Combo play, and Alaska. As of December 31, 2012, it had proved undeveloped reserves and proved developed reserves of approximately 271.4 million BBLs (MMBBLs) of oil, 103.0 MMBBLs of NGLs, and 714.6 billion cubic feet of gas. The company was founded in 1997 and is headquartered in Irving, Texas.