The sea of oil and natural gas underneath North Dakota is far larger than first thought.
There are 7.4 billion barrels of recoverable oil in the western part of the state and extending into Montana, according to the latest estimate by the U.S. Geological Survey.
That's more than twice the oil the USGS estimated could be recovered five years ago. What's more, the USGS has nearly tripled its estimate of the natural gas available in the area.
The revised totals could make the North Dakota field the greatest oil and gas find ever in the continental United States, topping the fabled East Texas field that made Texas synonymous with oil wealth. And it would put North Dakota second to Prudhoe Bay as the largest oil producer in U.S. history.
Experts within the energy sector believe the latest government estimate might have to be revised upward too.
"We think it's even a little bit conservative,'' said Ron Ness, president of the North Dakota Petroleum Council.
The new estimate will give fresh momentum to an economic boom within the state that has made it the fastest growing in the nation in both population and incomes. Per capita income has risen to $52,000 a year, sixth-highest in the nation, and once quiet farm towns have been overwhelmed by oil field workers, creating shortages of housing and services.
The USGS said the drilling of 4,000 wells since 2008 in what is known as the Bakken formation has given geologists a better idea of the riches underground. The new analysis also highlights the rapid ascent of North American oil and gas production driven by the advent of the technique known as hydraulic fracturing.