Environmentalists have long complained of potentially severe air and groundwater pollution from oil-shale projects.

Major investors are looking at restarting an oil-shale industry in Colorado, which has "a much thicker and richer deposit of oil shale" than Utah. There, Vanden Berg said, wells are producing oil from in-situ mining, in which the shale is heated underground.

Isaacson said about 85 percent of the United States' oil shale deposits are in Colorado, just over the state border near Vernal. Utah's share is 10 percent of the U.S. total.

Utah, Wyoming and Colorado together have oil-shale deposits with 1.5 trillion barrels of crude oil. Utah's portion is 150 billion barrels. If Utah and western Colorado oil shale were developed together, he said, the field "would rival Saudi Arabia."

Baza predicted that oil shale is a resource that will prove to be valuable eventually. "I wish I could tell you why there doesn't seem to be a strong business interest in it yet."

In June, the Bureau of Land Management issued a research development and demonstration lease to Oil Shale Exploration Co. for an experimental project about 45 miles southeast of Vernal. The lease is on the 160-acre site of the old White River Oil Shale Mine, which was abandoned.

The Bureau of Land Management once tried to close the mine but didn't complete the job because of a methane explosion. In June, when the lease was issued, company managing director Don Elcan said if the Shale Oil Exploration could produce oil at commercial levels and meet other requirements, it would be entitled to lease 4,960 adjacent acres for a commercial project.

In November, Elcan told Utah legislators the lease was effective July 1, 2007, and since then the company shipped 300 tons of product to Canadian laboratories for analysis.

"All three laboratories have designated the product as a medium sweet syncrude, which is fairly easy to refine into both diesel fuel and jet oil. So it is a very attractive product for refineries," he said.

Elcan added in six years, Oil Shale Exploration hopes to be producing 50,000 barrels per day.

Colorado boom busts

Richard Lamm was governor of Colorado during the last oil shale boom — and on Black Sunday, when it ended — recalled the disruptions caused by both. Oil shale projects in western Colorado were supposed to be on a stupendous scale. "What they were talking about at the time was like digging a new Panama Canal every six months," he said.