Washington ? The Bush administration Thursday took sweeping action to open nearly 60 million acres — about one-third of U.S. National Forest land — to new road construction, which in turn could lead to logging, mining and other commercial use of these previously protected areas.

Although lawsuits remain pending over the contentious issue, the plan undoes the “roadless rule” that President Clinton ordered in 2001 during his last days in office. It had banned more road construction on 58.5 million acres of U.S. national forests, nearly all of them in Alaska and 11 other Western states.

In announcing the new policy, Agriculture Secretary Mike Johanns, whose department includes the U.S. Forest Service, praised it as a cooperative and collaborative form of conservation.

“Our actions today advance President Bush’s commitment to cooperatively conserve inventoried roadless areas within our national forests,” Johanns said. He added that his department “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.”

Conservation groups, however, termed it a mammoth step backward.

“Millions of acres of our last wild forests are now immediately at risk,” said Robert Vandermark, director of the conservationist Heritage Forest Campaign, who noted that 386,000 miles of roads already exist in U.S. forest lands. “This leave-no-tree-behind policy paves the way for increased logging and mining in much of the nation’s last wild areas.”

Of the total area affected, road-building and subsequent commercial uses could be started immediately in 34.3 million acres because the Forest Service already has prepared management plans.

An additional 24.2 million acres ultimately could be opened to road construction and commercial development, but governors have 18 months to file petitions seeking to restore the “roadless rule” on sections of national forest in their states, or to offer new plans to allow and manage commercial uses.

A total of 38 states and Puerto Rico have National Forest land at least marginally affected by the roadless rule, but 97 percent of the acreage lies within Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming.