BEND -- A U.S. Supreme Court decision Monday upholding changes in federal grazing rules could hurt thousands of ranchers who run cattle and sheep on public lands, including almost 13 million acres in Oregon.

The unanimous court ruling, which upholds a number of regulatory changes adopted by the Department of Interior in 1995, was praised by environmentalists and blasted by cattlemen.

"This decision will totally devastate the rancher," said Glen Stonebrink, executive director of the 2,400-member Oregon Cattlemen's Association. Stonebrink said the regulations eliminate the assurance that ranchers with federal grazing permits will always have access to public lands. That access, he said, has been one of the foundations of many ranching operations in the West. "Ranchers really felt that they had a permanent right to the forage," he said.

However, Bill Marlett of the Oregon Natural Desert Association said it is past time for ranchers to lose that right. He doubted the ruling would have sweeping effects, but he said it was important nonetheless.

"This is just one step on the path of wresting control of public lands away from ranchers," he said.

In its 9-0 ruling, the court upheld three regulations that apply to the Bureau of Land Management. In addition to eliminating the preference that grazing permit holders had when their permits were up for renewal, the regulations for the first time allow nonranchers to hold grazing permits. The regulations also give the government title to any range improvements, such as fences and water systems, even if those systems were installed by the rancher.

The Public Lands Council, based in Washington, D.C., and other agricultural groups, sued the Interior Department in 1995, challenging the changes in the grazing regulations. The council represents four ranching and farming groups.

The rules were struck down by a Wyoming federal judge but later reinstated by a federal appeals court. When the Supreme Court agreed last fall to review the rules, ranching groups were delighted. But Monday's decision upheld the tougher restrictions.

About 20,000 ranchers have grazing permits on some 170 million acres of BLM land, most of it in the West. There are about 1,500 ranchers operating on just less than 13 million acres of BLM land in Central and Eastern Oregon.

Marlett doubts many of those ranchers will notice much change. He predicted the BLM would continue issuing grazing permits and leases to traditional holders, who would continue to run about as many cattle on the land as they always had.

But John Hays, a Baker County rancher and the president of the Oregon Cattlemen's Association, said the rule change is a real loss. He said grazing rights used to be considered inviolable. Ranchers would inherit them from their parents, even pay federal inheritance tax on them. Banks, he said, use them even today as collateral for loans. If those grazing permits are no longer guaranteed, he said, their value as real property will evaporate.

And that is where the real impact of the court's ruling will be felt, said Jon Marvel, head of an environmental group in Hailey, Idaho. He said banks factor in government grazing permits when they calculate a rancher's economic potential. Because those leases are less certain today, he said, banks will tighten the credit to those ranchers.

And because many ranchers are facing tough economic times, the loss of credit could doom many, he said. "This decision will result in the acceleration of the end of public land ranching," said Marvel, director of the Idaho Watersheds Project.