Vanguard Natural Resources is engaged the acquisition and development of oil and natural gas properties. At Dec 31 2015, Co. owned the following properties and oil and natural gas reserves: the Green River Basin in Wyoming; the Permian Basin in West Texas and New Mexico; the Gulf Coast Basin in Texas, Louisiana, Mississippi and Alabama; the Anadarko Basin in Oklahoma and Texas; the Piceance Basin in Colorado; the Big Horn Basin in Wyoming and Montana; the Arkoma Basin in Arkansas and Oklahoma; the Williston Basin in North Dakota and Montana; the Wind River Basin in Wyoming; and the Powder River Basin in Wyoming. At Dec 31 2015, Co.'s total estimated net proved reserves were 2,288.9 Bcfe.