The Covenant discovery, near Sigurd, Utah is 130 miles south of Salt Lake City and more than 100 miles from any of Utah's other major oil fields, according to an Associated Press report.

Wolverine, a privately held company with just 25 employees, found oil in late 2003, and by May 2004 it started producing from a single deposit estimated to contain 100 million to 200 million barrels of oil.

Now the company is examining 25 deposits that it and government geologists say could contain 1 billion barrels of oil, which would make it the largest domestic US find in 30 years.

Central Utah is a region with complex geology that has been long abandoned for exploration by major oil companies. Oil companies began exploring the area more than 50 years ago without success, producing only dry wells, even though Central Utah is part of an oil-producing belt that stretches from Mexico to Alaska, said Utah Survey petroleum section chief Tom Chidsey.

"The outcrops at the well and along the east side of Sevier Valley, especially near the mouth of Salina Canyon (are typically highly contorted and faulted – what you see at the surface does not necessarily reflect what exists 7,000 feet below,” Chidsey told the American Association of Petroleum Geologists’ magazine, Explorer .

"The real trick is to identify deep drilling targets using state-of-the-art seismic data, three-dimensional models, well information, high-quality surface geologic maps, geochemical analyses and other techniques," he said.

"The Covenant discovery demonstrates central Utah has all the right stuff – large ' anticlines, source rock, reservoir rock, sealing rock and good timing. Industry interest in the area is extremely high."

In 1999, Wolverine bought Chevron's leasing rights and seismic data and undertook additional seismic.

With just two wells operating at full capacity now, Wolverine is pumping 1,500 barrels of very high quality that is fetching a premium at at the Salt Lake refinery.