The Bush administration, in one of its biggest decisions on environmental issues, moved Thursday to open up nearly a third of all remote national forest lands to road building, logging and other commercial ventures.

The 58.5 million acres involved, mainly in Alaska and in western states, had been put off limits to development by former President Clinton, eight days before he left office in January 2001.

Under existing local forest management plans, some 34.3 million acres of these pristine woodlands could be opened to road construction. That would be the first step in allowing logging, mining and other industry and wider recreational uses of the land. Under proposed rules, new management plans have to be written for the other 24.2 million acres before road building can commence.

Governors have 18 months to submit petitions to the U.S. Forest Service, challenging either the old plan to stop development, or calling for new plans to allow it.

Agriculture Secretary Mike Johanns (search) said in announcing the rule that his agency "is committed to working closely with the nation's governors to meet the needs of our local communities while protecting and restoring the health and natural beauty of our national forests."

The Agriculture Department, which includes the Forest Service, said governors can base their petitions on requests to protect public health and safety; reduce wildfire risks to communities; conserve wildlife habitat; maintain dams, utilities or other infrastructure; or ensure that citizens have access to private property.

The Forest Service, which will review and have final say over the petitions, calls the new process voluntary and is setting up a national advisory committee on the rule. "If a governor does not want to propose changes ... then no petition need be submitted," the agency says in briefing documents obtained by The Associated Press.

Roadless areas in national forests stretch among 38 states and Puerto Rico. But 97 percent, or 56.6 million acres, are found in 12 states: Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming.

Environmentalists say the new rule also would let the administration rewrite the forest management plans to lift restrictions against development on most of that forest land.

"Yesterday, nearly 60 million acres of national forests were protected and today as a result of deliberate action by the administration they are not," said Robert Vandermark, director of the Heritage Forests Campaign, run by a coalition of environment groups. "The Bush administration plan is a 'leave no tree behind' policy that paves the way for increased logging, drilling and mining in some of our last wild areas."

The Clinton-era rule has been much debated in federal court.

A federal court in Idaho had issued a preliminary injunction against the roadless rule in 2001, but the San Francisco-based U.S. Court of Appeals for the 9th Circuit overturned the injunction based on an appeal by environmental groups.

Then in 2003, a federal court in Wyoming overturned the rule. Many of those same groups appeals to the Denver-based U.S. Court of Appeals for the 10th Circuit, which heard arguments Wednesday.

The Forest Service believes its new rule "helps us to move forward with a policy that is not clouded by legal uncertainty, as was the case with the 2001 rule," says a current agency document entitled "National Key Messages & Talking Points."

Jim Angell, an attorney with Earthjustice law firm in Denver, who argued the case, called that just an excuse for pushing through a new rule that represents "a huge step back for the protection of our most pristine lands."

"Really, this is an effort to rush this rule through before the 10th Circuit can reverse that Wyoming judge, just like the 9th Circuit did before," he said. "It's incredibly cynical of them to use that judge's ruling as an excuse."