Bill Barrett Corporation explores for and develops oil and natural gas in the Rocky Mountain region of the United States. As of December 31, 2011, the Company had four active development programs, including the Gibson Gulch area in the Piceance Basin, the Uinta Oil Program in the Uinta Basin, the West Tavaputs area in the Uinta Basin and, following an acquisition in August 2011, a primarily oil program in the Denver-Julesburg Basin. The Company holds acreage in a number of basins with plans for drilling activity in the Powder River, Southern Alberta, Paradox and San Juan Basins. Among its four key development programs, three of the programs target oil and high British Thermal Unit (BTU) content natural gas that can be processed into natural gas liquids (NGLs), while its exploration program is exclusively focused on oil and high BTU content natural gas. On December 31, 2012, the Company sold its natural gas assets to an affiliate of Vanguard Natural Resources, LLC.