Amid discussions about restoring grizzly bears to the North Cascades and the recent reintroduction of cat-like creatures called fishers to the region, conservation groups are seeking protection for another elusive carnivore that was historically more common in area mountains.

Nine groups are calling on the federal government to list the wolverine as threatened under the Endangered Species Act.

The wolverine is a creature between about 20 and 40 pounds, with a bushy tail and white markings on its otherwise dark brown body, according to the U.S. Fish & Wildlife Service. They will hunt small animals, scavenge what’s left of carcasses hunted by other predators, and eat fruit when available.

Estimates from government agencies and conservation groups suggest a few dozen wolverines may remain in the North Cascades and no more than 300 nationwide.


Despite their small numbers, conservation groups and the Fish & Wildlife Service have been fighting for about 25 years over the merits and urgency of protecting the species.

Most recently, the regional nonprofit Conservation Northwest joined the Center for Biological Diversity and other groups in issuing a notice of intent to sue the Fish & Wildlife Service if the agency does not fulfill its duties under the Endangered Species Act.

“Wolverines have been waiting far too long for the protection they need under the Endangered Species Act,” Center for Biological Diversity attorney Andrea Santarsiere said in a Jan. 16 news release accompanying the notice. “Delays are deadly when it comes to protecting wildlife. Wolverines need help right now.”

The Fish & Wildlife Service said in an email Friday that it continues to evaluate whether the species needs protection.

“The U.S. Fish and Wildlife Service has been working with scientists around the world, and our state and federal partners, to gather and analyze the best available science on the wolverine to determine if it warrants protection under the Endangered Species Act,” the statement reads. “We expect to publish our findings in the Federal Register before the end of the calendar year.”

Little is known about the animals at the center of the potential lawsuit. They are typically only seen by wildlife biologists who plant cameras in their alpine habitat, or sometimes by lucky mountaineers.

“The elusive wolverine has long been a subject of folklore,” states the notice of intent.

A North Cascades National Park Service Complex fact sheet calls wolverines “one of the rarest mammals in North America and the least known of the large carnivores.” They were rediscovered in the North Cascades in 1995 during surveys for other wildlife.

A decade later, the U.S. Forest Service Pacific Northwest Research Station began studying wolverines in the North Cascades.

The movements of 13 wolverines captured and fitted with tracking devices between 2005 and 2014 revealed they use large areas primarily along the Cascades crest from Skagit Valley Provincial Park in British Columbia to the Lake Chelan area, according to a report published in 2014. At least four of the wolverines came into east Skagit County.

A male called Rocky and a female called Xena, who are believed to have had offspring together, were among four wolverines that ventured near Marblemount, according to a study map. Researchers photographed Xena with a young wolvervine one year and DNA analysis of a young male wolverine that was trapped suggests it was the son of Rocky and Xena.

PNW Research Station satellite ranges.jpg

The general range of movement is shown for 10 wolverines captured and fitted with satellite transmitters between 2006 and 2014. Four of them ventured near Marblemount during the study.


Wildlife biologists continue studying the wolverines that live in remote areas of the North Cascades using cameras and run-poles, which are wooden platforms equipped with bait to entice the animals, brushes to capture hair samples and cameras to capture photos.

“Run-poles are designed to entice the wolverine to go out on the post, look up at the bait and then the photo is taken,” said Robert Long, a wildlife biologist at Woodland Park Zoo in Seattle who specializes in carnivore research throughout the Northwest. “Brushes or clips on the pole capture the hair sample, called hair snags or hair sampling devices.”

Hair samples and photos can be used to identify individual animals and get a better understanding of the population. From the hair, DNA can be analyzed. From photos, distinctive patches of lighter fur — similar to unique features on harbor porpoises or orca whales — can be used to distinguish one animal from another.

Conservation Northwest’s Wildlife Monitoring Program maintains cameras in the North Cascades to track wolverines and other species. The most recent annual report shows three wolverines were detected in the area in 2018.

Lauren Baum, Conservation Northwest’s Citizen Wildlife Monitoring Project coordinator, said in the North Cascades the organization has seen most wolverine activity in Whatcom County, in areas around Mount Shuksan to the east of Mount Baker.

In January 2018, one wolverine was photographed near Pass Creek northeast of Baker Lake.

“They are certainly in eastern Skagit County as well, though the population in the Cascades remains low,” Conservation Northwest Communications Director Chase Gunnell said.


The wolverine is the largest land-dwelling member of the weasel family and is related to the smaller fisher that is being brought back to the North Cascades.

Wolverines once roamed across large swaths of mountainous territory throughout the western U.S., according to the Fish & Wildlife Service. The species was largely eradicated through trapping and habitat loss during the early 1900s.

There are now small populations of wolverines in pockets of mountain habitat across five states.

“Currently, wolverines occur within the North Cascades Range in Washington and the Northern Rockies of Montana, Idaho, Wyoming and a small portion of Oregon (Wallowa Range),” a Fish & Wildlife Service document states. “Populations once existed in the Sierra Nevada of California and the southern Rocky Mountains in the states of Colorado, Wyoming, and New Mexico.”

The small, fragmented populations that persist are at risk of losing more of their habitat because of climate change.

Wolverines use dens dug into deep mountain snowpack for raising their young. As global temperatures warm, that snowpack will continue to decline.

The Fish & Wildlife Service acknowledged that threat in some of its findings.

“Extensive climate modeling indicates that the wolverine’s snowpack habitat will be greatly reduced and fragmented in the coming years due to climate warming, thereby threatening the species with extinction,” states the Fish & Wildlife Service’s 2013 proposal to list the species as threatened. “Wolverines are dependent on areas in high mountains, near the tree-line, where conditions are cold year-round and snow cover persists well into the month of May.”

overlap with snow PNW Research Station study.jpg

During two years of the Pacific Northwest Research Station’s study of wolverines in the North Cascades, about 90% of the location data obtained overlapped with areas where snow cover lasts into spring.

The next year, the agency withdrew that proposed listing, stating that the wolverine had made a steady recovery since the 1960s and arguing that the effects of climate change on the species were not clear.

Long said that while photo and DNA evidence has shown wolverines have returned to the North Cascades, possibly from Canada, how many are in the region is impossible to say.

“We don’t know that much about the species,” he said. “We don’t have a perfect sense of how many were here or how many the Cascades can support.”

Long is involved in ongoing research of the North Cascades wolverine population, helping to monitor and learn more about the animals in coordination with nonprofits and government agencies.

“We have been working to develop methods so we can track the recolonization of wolverines to the North Cascades and then long term track how they respond to climate change, development, increased recreation in the backcountry, things like that,” he said.

Amid the surge of research in recent years, the Skagit Environmental Endowment Commission that supports efforts to protect the Skagit River watershed upstream of the Ross Dam produced a video about the wolverine to highlight the mysterious animal and show support for its protection.

“Since they are such a wily animal and so little is known, that’s one reason for listing them under the federal act,” Skagit Environmental Endowment Commission U.S. Chair Leo Bodensteiner said. “Plus, with the particular threat of climate change, I think this is an animal that certainly deserves listing.”


The same conservation groups threatening to file a lawsuit have fought for the wolverine before.

In 2016, a U.S. District Court of Montana judge ruled in their favor, ordering the Fish & Wildlife Service to revisit its 2013 proposal to list the wolverine as threatened.

“If there is one thing required ... under the ESA, it is to take action at the earliest possible, defensible point in time to protect against the loss of biodiversity within our reach as a nation. For the wolverine, that time is now,” Judge Dana Christensen said in the April 4, 2016, decision.

At issue now is that in the years since Christensen’s ruling, the wolverine has remained unprotected.

“Three years have passed since the Montana court’s decision with no action by the Service on this issue,” states the notice of intent to sue that was sent to the Fish & Wildlife Service and U.S. Department of the Interior, which oversees the agency. “The Service is, therefore, in violation of the ESA.”

Conservation groups have been fighting the Fish & Wildlife Service over the state of wolverine populations since 1994, when a lawsuit filed by the Biodiversity Legal Foundation, which later merged with the Center for Biological Diversity, first asked the federal agency to list the wolverine as a threatened or endangered species.

That organization’s second lawsuit seeking protection for the wolverine, filed in 2000, included statements from the state Department of Fish & Wildlife that hundreds of wolverine pelts were reported in Hudson’s Bay Co. trapping records from the mid-1800s.

Long said fossil evidence also shows that wolverines were present in parts of Washington state for hundreds of years.

Those continuing to fight for Endangered Species Act protection for the wolverine argue populations in the North Cascades and other mountain regions have not recovered from near elimination during fur-trapping days and that those that remain face increasing threats due to climate change.

The judge on the case in 2016 agreed.

“No greater level of certainty is needed to see the writing on the wall for this snow-dependent species standing squarely in the path of global climate change,” Christensen said in the ruling.

— Reporter Kimberly Cauvel: 360-416-2199,, Twitter: @Kimberly_SVH,

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