Pioneer Natural Resources is an independent oil and gas exploration and production company. The company was created in 1997 by the merger of Parker & Parsley Petroleum Company and MESA Inc. Pioneer Natural Resources' main business is the exploration and production of oil, natural gas liquids, and gas reserves. Pioneer Natural Resources is historically a Texas-based oil company. Pioneer is one of the most active drillers in Texas’ Spraberry/Wolfcamp oil field in the Permian Basin and the Eagle Ford Shale play in South Texas. It is also one of the largest natural gas operators in southeastern Colorado's coal bed methane-rich Raton Basin and in the gas fields around Hugoton, Kansas and in the western part of the Texas Panhandle. Its operations include ongoing drilling programs in Texas’ liquids-rich Barnett Shale and in Alaska’s Oooguruk oil field, where Pioneer became the first independent operator to produce oil on the North Slope in 2008. In June 2010, Pioneer Natural Resources announced a $1.15 billion Eagle Ford Shale joint venture with Reliance Industries.