COEUR D'ALENE, Idaho (AP) - A federal judge has reopened popular snowmobile trails in northern Idaho that had been closed to protect caribou.

The ruling by U.S. District Judge Robert Whaley in Spokane, Wash., on Tuesday lifted the snowmobile ban from the caribou recovery zone in the Idaho Panhandle National Forests surrounding Priest Lake.

"I've never seen anything like this," said Mark Sprengel of the Conservation Alliance. "This blindsided us. It contravenes all available science."

Craig Hill, a resort owner on the west shore of Priest Lake, said he was ecstatic with the ruling.

"This couldn't have happened at a better time," he told The Spokesman-Review. "It's something that's going to save the winter economy at Priest Lake."

Whaley banned snowmobiles in September on nearly 470 square miles of national forest land in northern Idaho after conservation groups argued the last mountain caribou herd in the contiguous 48 states needed protection.

The machines, they argued, were able to penetrate far into the area and force caribou to expend energy they couldn't afford to lose to survive the winter. They also said the compacted trails the snowmobiles left made it easier for cougars to reach caribou calving grounds.

Up to 40 caribou are believed to inhabit the caribou recovery zone in the Idaho Panhandle National Forests.

In banning snowmobiles in September, Whaley gave environmentalists and snowmobilers time to work out an agreement, and they did. However, the U.S. Forest Service didn't approve the plan and made a different recommendation allowing more snowmobile access.

A sticking point was a loop trail around the north end of Priest Lake that environmentalists say cuts across important caribou habitat but that snowmobilers say connects trail networks on opposite sides of the lake. Whaley's ruling allows the trail to open.

In a separate ruling in December, Whaley banned snowmobile trail grooming in the area, and few were willing to endure the bumpy trails, although snowmobiling was still allowed. His ruling Tuesday allows grooming to resume on trails near Bonners Ferry.

Whaley's most recent ruling also allows off-trail riding in the Roman Nose-McCormick Ridge area and in the Trapper Burn area.

"Essentially, that's opening up the whole caribou recovery area," Sprengel said. "This is the most bizarre thing I've ever seen. The Forest Service is taking a more pro-motorized sports approach than the snowmobilers were. Their priorities are seriously out of whack here."

Dave O'Brien, a spokesman for the Idaho Panhandle National Forests, said the agency followed guidelines provided by state and federal caribou experts.

"We put forth a proposal based on the biology of the caribou," O'Brien said.