The answer to rising fuel prices may lie under millions of acres of federal land, mostly in the West, that for a variety of reasons are off limits to oil and natural-gas development, according to the Bureau of Land Management.

A BLM inventory of public lands released Wednesday shows 279 million acres of untapped resources throughout the United States. Those areas contain an estimated 31 billion barrels of oil and 231 trillion cubic feet of natural gas.

"If we want to lower the cost of energy, we must be willing to use our own energy resources as part of a balanced and rational energy policy," Stephen Allred, assistant secretary of the interior, said in a conference call with reporters.

The report found 60 percent of federal lands that have potential for oil and natural gas are closed to leasing, mostly as a result of congressional or administrative mandates.

The report drew sharp criticism from a leading member of Congress for oversimplifying the nation's energy woes.

House Natural Resources Committee Chairman Nick Rahall, D—West Virginia, pointed out that drilling on federal lands has increased steadily since 2000 — even as gas prices rose. He said the BLM report gives the "absolutely false impression" that more drilling equates to cheaper energy prices for consumers.

"We simply cannot drill our way to lower prices at the pump," Rahall said.

For Utah, the BLM inventory totaled 40.3 million acres of federal land with potential for an estimated 880.4 million barrels of oil and 22.1 trillion cubic feet of natural gas.

The report does not include state or private lands, which generally have had fewer restrictions on drilling. It also does not address the estimated trillion barrels of oil in shale in Utah and throughout the Intermountain West.

Just last week, Gov. Jon Huntsman Jr. submitted a letter to the U.S. Senate asking it to lift a moratorium on the development of Utah oil shale, most of which is on BLM land.

But Pam Miller, chairwoman of the Nine Mile Canyon Coalition in central Utah, is skeptical about claims that developing oil on public lands would lower gas prices. Her group is at odds with a company extracting natural gas from the West Tavaputs Plateau, a fragile archaeological site and wilderness study area.

"How am I supposed to believe the prices are going to go down if they go in and drill in these special places?" she said. "It's a scare tactic to say prices are going up if we don't do this."

All federal land believed to have energy potential was included in the study, the third in a series of scientific reports required by the Energy Policy and Conservation Act of 2000.

The United States consumed about 7.5 billion barrels of oil in 2006, 60 percent of which was imported, the study says. Federal lands produced about 5 percent of the 2006 consumption.