In 2013, the U.S. Fish and Wildlife Service (USFWS) proposed to list the wolverine in the lower 48 states as endangered.
In October, the agency announced the wolverines will not be protected. It cited research saying the animal, which looks like a small bear with a bushy tail and is related to the weasel, moves across the Canadian border in both directions, and there is enough snow in springtime for denning.
But conversation groups believe the government has not looked at all the science.
"The science really overwhelmingly points in one direction that climate change will significantly reduce spring snowpack in the Wolverines habitat in the lower 48," said Earthjustice associate attorney Amanda Galvan. "So, the Fish and Wildlife Service kind of ignored this gloomy reality by cherry picking only the data that appears to support its conclusions."
Wildlife officials estimate there are 250 to 300 wolverines in Wyoming, Montana, Idaho and Washington states. The agency has yet to respond to the lawsuit.