Reuters: An oil-rich region of the north-central United States holds more than twice the recoverable crude supplies estimated just five years ago, according to a government study that highlights the nation's march toward energy self-sufficiency.
The Bakken Formation and Three Forks Formation, which spans parts of Montana, North Dakota and South Dakota together hold an estimated 7.4 billion barrels of undiscovered, technically recoverable oil, the U.S. Geological Survey study said, although energy experts...