The Clinton administration in November expanded a plan to restrict logging, mining and road building on some of the nation’s most pristine and remote national forest land.

The plan, which still could be revised, would protect 58.5 million acres, an area nearly the size of Oregon that encompasses almost a third of all national forest land.

The major change from the original proposal announced in May was the inclusion of 9.3 million acres in the Tongass National Forest in Alaska.

“There are certainly landmark events in the history of conservation — this clearly is one of those landmark events,” said Jim Lyons, the Agriculture Department undersecretary who oversees the Forest Service. “We are responding to the will of the American people.”

But many forest industry groups said the plan is too restrictive. And Sen. Larry Craig, R-Idaho, predicted the proposed rule would be overturned in court and said he is examining ways to thwart the plan legislatively. “I’m not going to leave a stone unturned,” he said.

The rule may have little impact in the Bay watershed. About 90 percent of the roadless areas in the George Washington National Forest in Virginia, much of which is in the watershed, is already in compliance with the national proposal, meaning new roads cannot be constructed there.

The plan tightens restrictions on logging, allowing timber harvests and development in “roadless” areas only in certain circumstances, such as to reduce the risk of wildfires and to aid endangered species. The earlier version of the plan left it up to local forest managers to decide whether to restrict logging.

Administration officials changed the plan after receiving more than 1.5 million comments at public hearings and through written correspondence, agency officials said.

Under the new plan, the protections would be extended to the Tongass in 2004, a move that would reduce the expected annual logging level from all roadless areas by 85 percent. The original plan was criticized by conservationists because it delayed until 2004 a decision on whether to include the roadless acres in the Tongass, the nation’s largest national forest.

Environmentalists have been pressing for years for a ban on road-building because they believe the pathways increase erosion, disrupt wildlife habitat and make it easier for logging trucks and mining operators to reach remote public lands.

Michael Francis, an environmentalist with The Wilderness Society, said the new plan rates as one of the top land preservation accomplishments of the past 100 years, along with passage of the Wilderness Act and President Theodore Roosevelt’s creation of national forests. “The Forest Service actually did listen to 1.5 million people and moved the ball forward,” he said.

The announcement is the next-to-last step in the process for crafting a rule without the involvement of Congress. Agency officials will decide whether to make more changes before they publish a final rule in mid-December, just a month before President Clinton leaves office.

The rule will not take effect until mid-February, because of a federal law that delays new rules for 60 days if they have an economic impact of more than $100 million.