Saying the risk of catastrophic fire remains too high in Sierra Nevada forests, the Bush administration on Tuesday endorsed new rules to more than double the amount of logging allowed on 11 million acres of national forests from Redding to Bakersfield. The new rules rewrite the "Sierra Nevada Framework," a landmark plan approved in 2001 by the U.S. Forest Service under the Clinton administration. That plan, considered by environmentalists to be a key piece of Clinton's environmental legacy, placed more emphasis on wildlife and recreation than commercial logging on 11 national forests in the Sierra. Those forests stretch 400 miles and include Lake Tahoe and the sequoia forests above Bakersfield. On Tuesday, environmental groups called the changes a giveaway to the timber industry that would harm salmon, the California spotted owl and other wildlife that inhabit the forests, which make up more than 10 percent of the state. But Bush administration leaders said the Clinton plan relied too heavily on controlled burns and didn't allow adequate thinning of overgrown forests, leaving hundreds of rural towns at risk. "The old plan came up short," said Jack Blackwell, regional forester for the U.S. Forest Service's California-Nevada region. "In hindsight, it was overly cautious." The changes endorse recommendations from a team of Forest Service employees whom the Bush administration appointed to review the plan. Across the Sierra, as with much of the West's forests, a debate has raged in recent years about how to undo the damage from Smokey Bear - the policy of preventing forest fires. Historically, the pine and fir forests of the Sierra Nevada burned about every 15 years, removing dead wood, fertilizing the soil and opening seed cones on some tree species. But starting around World War I, the federal and state government began putting out wildfires. As a result, some areas of the Sierra have not burned in nearly 100 years. Thick underbrush provides huge amounts of fuel, so that when fires do start by lightning or human carelessness, they can burn for weeks. "Firefighters today are having to attack forest fires that their fathers and grandfathers never experienced," said Blackwell. "There is a real concern about firefighter safety, along with communities, property and wildlife." Under the new Sierra plan, the Bush administration directs the Forest Service to: - Increase the total annual cut to 450 million board feet a year. That compares with Clinton-era logging limits of 191 million annually from 2001 to 2006, and 108 million a year in the five years after that. Logging levels in the Sierra in the late 1980s totaled about 1 billion board-feet. It takes about 10,000 board-feet to build an average-sized house. - Cut larger trees to help defray the costs of thinning. Under the Clinton plan, trees up to 30 inches in diameter could be logged within a half-mile of communities. But in more remote areas, 20 inches was the limit, and in old-growth forests, 12 inches was the limit. Under the Bush plan, loggers could cut trees up to 30 inches in all areas. - Allow loggers to remove 60 percent of the canopy in a forest. The limit was 50 percent under the Clinton plan. Blackwell said allowing the cutting of larger trees is necessary so timber companies can make a profit on thinning brush and small trees. Otherwise, he said, costs to taxpayers can total $1,000 per acre to treat forests. Jay Watson, California director of the Wilderness Society, said environmentalists are disappointed and may sue. "Yes, there is a need to thin forests in the Sierra Nevada," Watson said. "The original framework was a thinning plan, but their changes take it to a logging plan." Mike Dombeck, a Wisconsin biologist who served as chief of the Forest Service under the Clinton administration, said he regrets the changes. "The original plan had input from our best scientists both inside and outside the Forest Service," Dombeck said. "Apparently now the efforts are to increase commodity extraction." In California, logging levels have fallen dramatically because of tougher environmental rules and endangered species rulings from courts. Statewide, the overall cut on public and private lands is down about 60 percent since 1990. "I think the Clinton administration was convinced by environmentalists that prescribed fire was the only real method that should be used to reduce fire risk in the Sierras because all logging was bad," said Dave Bischel, president of the California Forestry Association, a timber industry group in Sacramento.