An auditor told Congress last week that the Green River Formation in Wyoming, Utah and Colorado contains about as much oil as the "entire world's proven reserves," making it the "world's largest deposits of oil shale."

The formation is largely — about 75 percent — on federal Bureau of Land Management lands in the states, making it possible for the government to extract funding from the shale formation almost as well as the companies that may extract the oil.

Anu Mittal, director of natural resources for the federal General Accounting Office, said the U.S. Geological Survey estimates 3 trillion barrels of oil in the 1,000-foot sedimentary rock formations under the three states. She said about half of the oil should be technically recoverable, "depending on available technology and economic conditions."

The standard royalty rate for a company to extract oil on federal lands amounts to 12.5 percent, and has been in place since the 1920s, according to Secretary of the Interior Ken Salazar, who said he is studying how to boost that royalty in the future.

Assuming static prices of oil and equal distribution of recoverable shale, at about $100 per barrel, extraction of 75 percent of 1.5