State urging U.S. Geological Survey to finish oil reserve study

State officials want the U.S. Geological Survey to complete a study on the expansive Bakken shale formation where estimates of oil reserves range from as low as 10 billion barrels to as high as 500 billion.

The Bakken encompasses some 25,000 square miles in North Dakota, Montana, Saskatchewan and Manitoba. About two-thirds of the acreage is in western North Dakota.