Emerald Oil, Inc. offers exploration, development, and production of oil and gas in the United States. The company focuses on oil and natural gas properties primarily located in Montana, North Dakota, Colorado, and Wyoming. As of September 4, 2012, it controlled approximately 200,000 net acres in 5 primary prospect areas comprising 43,600 core net acres targeting the Bakken and Three Forks shale oil formations in North Dakota and Montana; 45,000 net acres in a joint venture in the Sandwash Basin Niobrara shale oil play, located in Mofatt and Routt counties, Colorado and Carbon County, Wyoming; 33,500 net acres in a joint venture targeting the Heath shale oil formation in Musselshell, Petroleum, Garfield, and Fergus Counties of Montana; 2,400 net acres in the Denver-Julesburg Basin targeting the Niobrara shale oil formation in Colorado and Wyoming; and 74,700 net acres in a joint venture in and around the Tiger Ridge natural gas field in Blaine, Hill and Chouteau Counties of Montana. The company was formerly known as Voyager Oil & Gas, Inc. and changed its name to Emerald Oil, Inc. in September 2012. The company was founded in 2008 and is based in Denver, Colorado.