BILLINGS, Mon. -- The tenacious wolverine, a snow-loving carnivore sometimes called the "mountain devil," is being added to the list of species threatened by climate change -- a dubious distinction that puts it in the ranks of the polar bear and several other animals that could see their habitats shrink drastically due to warming temperatures.

U.S. wildlife officials on Friday will propose Endangered Species Act protections for the wolverine in the contiguous 48 states, a step denied under the Bush administration.

The Associated Press obtained details of the government's long-awaited ruling on the rare, elusive animal in advance of the announcement.

Wildlife advocates, who sued to force the government to act on the issue, said they hope the animal's plight will be used by the Obama administration to leverage tighter restrictions on greenhouse gas emissions. As with the polar bear, the government could sidestep that thorny proposition by not addressing threats outside the wolverine's immediate range.

Only 250 to 300 wolverines roam the contiguous U.S., clustered into small, isolated groups primarily in the Northern Rockies of Montana, Idaho, Wyoming and Washington. Larger populations persist in Alaska and Canada.

Maxing out at 40 pounds (18 kilograms) and tough enough to stand up to grizzly bears, the animals will be no match for anticipated declines in deep mountain snows that female wolverines need to establish dens and raise their young, scientists said.

Yet because that habitat loss could take decades to unfold, wildlife officials said there's still time to bolster the population, including by reintroducing them to the high mountains of Colorado.

A special rule proposed by the Fish and Wildlife Service would allow Colorado's wildlife agency to reintroduce an experimental population of the animals that eventually could spill into neighbouring portions of New Mexico and Wyoming.

Federal officials also want to shut down wolverine trapping in Montana, the only one of the 48 affected states where the practice is still allowed.

Federal officials said other human activities -- from snowmobiling and skiing to infrastructure development and transportation corridors -- are not significant threats to wolverines and would not be curtailed under Friday's proposal.

Once found throughout the Rocky Mountains and in California's Sierra Nevada mountain range, wolverines were wiped out across the 48 states by the 1930s due to unregulated trapping and poisoning campaigns, said Bob Inman, a wolverine researcher with the Wildlife Conservation Society.

In the decades since, they've largely recovered in the Northern Rockies but not in other parts of their historical range, he said.