Troy A. Cook Laura N.R. Roberts Christopher J. Schenk Michael D. Lewan Lawrence O. Anna Stephanie B. Gaswirth Paul G. Lillis Timothy R. Klett Ronal R. Charpentier Richard M. Pollastro 2008 Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered volumes of 3.65 billion barrels of oil, 1.85 trillion cubic feet of associated/dissolved natural gas, and 148 million barrels of natural gas liquids in the Bakken Formation of the Williston Basin Province, Montana and North Dakota. application/pdf 10.3133/fs20083021 en Geological Survey (U.S.) Assessment of Undiscovered Oil Resources in the Devonian-Mississippian Bakken Formation, Williston Basin Province, Montana and North Dakota, 2008 reports