BISMARCK, N.D. — The government estimates up to 4.3 billion barrels of oil can be recovered from the Bakken shale formation in North Dakota and Montana, using current technology.
The U.S. Geological Survey calls it the largest continuous oil accumulation it has ever assessed.
An assessment by USGS in 1999 found the Alaska National Wildlife Refuge had 10.3 billion barrels of recoverable oil, said Brenda Pierce, a geologist for the agency
The Bakken Formation encompasses some 25,000 square miles in North Dakota, Montana, Saskatchewan and Manitoba....