They were warned, but they didn't listen.

Now, the U.S. Bureau of Land Management must deal with a federal judge's finding that the agency failed to properly consider potential damage to air quality and ancient rock art before selling oil and gas leases on sensitive public lands in Utah.

In an unusual weekend ruling, U.S. District Judge Ricardo Urbina issued a temporary restraining order to indefinitely block 77 protested oil and gas leases on more than 103,000 acres in eastern and southern Utah.

The ruling throws the already-disrupted Dec. 19 auction into deeper limbo.

Should Urbina continue to rule in favor of the seven conservation and historic-preservation organizations that sued to stop the BLM auction, the land-use plans that were the bedrock of the lease sale ultimately could crumble.

"We're on the cusp of something very significant," said Southern Utah Wilderness Alliance staff attorney Steve Bloch.

The parcels Urbina ruled on are near Arches and Canyonlands national parks, Desolation Canyon, Dinosaur National Monument, wilderness study areas and Nine Mile Canyon, revered as holy by the Hopi tribe.

Thirteen of the leases are those a University of Utah student won at the auction, with no intention to pay, in what he called an act of civil disobedience.

BLM spokeswomen in Salt Lake City declined to comment on the ruling because Urbina is still considering the underlying lawsuit.

But Pam Miller, a spokeswoman for the Nine Mile Canyon Coalition said: "We're thrilled. The judge thinks [the lawsuit] has merit and thinks they will prevail when it goes to court."

In his ruling, Urbina found the BLM didn't properly analyze air-quality damage that would result from industrial activity -- a measure the Environmental Protection Agency had advised the BLM to take to satisfy federal law.

Urbina also found that the BLM's inadequate studies posed risks to Nine Mile Canyon's ancient Puebloan art, protected under federal historic preservation law.

The judge based his ruling on three of the long-term resource management plans the BLM made final on Halloween. Those RMPs also were final environmental impact statements; Urbina wrote that the BLM "cannot rely on EISs that lack air pollution and ozone level statistics."

That means the resource plans for the Vernal, Price and Moab field offices could be in trouble, Bloch said. "At a minimum, these three RMPs suffer fatal flaws."

About a half-dozen of the 77 leases were on the West Tavaputs Plateau, where Bill Barrett Corp. is seeking full-field development of about 900 natural gas wells. The final environmental impact statement on that project, expected before President George W. Bush left office, has yet to emerge.

Bill Barrett spokesman Duane Zavadil declined to comment on the specifics of Urbina's ruling because the company has intervened in the lawsuit. He did say, however, that the project's environmental studies include ozone analyses.

Industry representatives said the lawsuit against the lease sale was counterproductive.

"It's unfortunate that this ruling came just days before President Obama was sworn in since it will result in a setback for two of his main policy goals -- increasing energy security and reducing greenhouse gas emissions," said Kathleen Sgamma, government affairs director for the Independent Petroleum Association of Mountain States.

But Tim DeChristopher, the 27-year-old economics student who threw a wrench into the lease sale, hailed Urbina's ruling even though he has criticized mainstream environmental groups' legal fights as games they are losing.

DeChristopher, who won bids worth $1.8 million on 22,000 acres, said his actions were effective.

He still faces possible federal felony charges, but the temporary restraining order could work in his favor. "It is a ruling that says this auction was inappropriate in the first place," he said.

phenetz@sltrib.com