Vanguard Natural Resources, LLC (Vanguard) is focused on the acquisition and development of oil and natural gas properties in the United States. Through the Company�s operating subsidiaries, it owns properties and oil and natural gas reserves located in nine operating areas: the Arkoma Basin in Arkansas and Oklahoma; the Permian Basin in West Texas and New Mexico; the Big Horn Basin in Wyoming and Montana; the Piceance Basin in Colorado; South Texas; the Williston Basin in North Dakota and Montana; the Wind River Basin in Wyoming; the Powder River Basin in Wyoming; and Mississippi. On December 22, 2011, the Company acquired additional working interest in the certain oil and natural gas properties located in Mississippi. On June 29, 2012, the Company acquired natural gas and liquids assets from Antero Resources. On December 31, 2012, it consummated the previously announced acquisition of natural gas and liquids assets from Bill Barrett Corporation.