The Phantom of the Rockies

Mist rises off the river, wetting our faces as we ford with chunks of slush bouncing off our waders. Stabbing the riverbed with ski poles, Mike Schadell and I struggle through the swift current, trying to find purchase on slimy river cobblestones. Our packs are weighed down by skis, dangling boots, three days of gear and a deer’s hindquarter.

We’re in Glacier National Park for an ongoing, multiyear, parkwide, noninvasive citizen science wolverine study in January 2010. Biologists had gathered data to estimate how many wolverines reside within the protected area’s boundaries. We each carry deer hindquarters to lure the largest mustelids to a post where steel wool brushes snag the animal's hair, which we will gather and use to collect DNA. 

Once across the river, we ski the undulating terrain through a mosaic forest of burnt black lodgepole pine, Douglas-fir and still-living, needleless larch trees. A fire raged through here years ago charring most of the woods. Deer, moose and wolf tracks punctuate the snow. A pine marten, a smaller member of the mustelid family, scampers from behind a tree. Its curiosity outweighs its elusive nature for a moment before it darts back into a dark hole at the base of an upturned root wad. 

Behind every tree, I imagine a 40-pound wolverine hiding in the shadows, watching us pass and smelling the bait we carry. Just imagine a medium-sized, dark chocolate-colored creature with tannish-blond streaks flanking its sides, the same color as the forest mosaic, phantoming through the forest and lunging across mountains. They resemble an elongated grizzly cub with short legs. Their fur coloration can vary from black to blond to brown. Each chest pattern is unique to that individual, like a human fingerprint.

Wolverines are the most prominent members of the weasel family. Their Latin name is Gulo gulo, meaning glutton, because they can eat large quantities of food. They have several nicknames, including Demon Beast, Indian Devil, Demon of the North, Skunk Bear, and Carcajou. 

This story explores the study of wolverines, their abilities, physical characteristics, habitats, survival needs, and the legal battles they continue to face. 

Douglas Chadwick, author of The Wolverine Way, shares an old Native American story from his book where a grizzly sow gave birth to four cubs. One was a runt and the other three always picked on the little one. When the runt grew up, it ran off and became the wolverine, wily and full of piss and vinegar, fierce and fearless, willing to stand up to bears and packs of wolves for food. 

After skiing several miles to the frozen lake’s foot, we pull out binoculars, glassing for megafauna … Nothing stirs. Winter hushes the surrounding landscape, but animal signatures and stories plot the snow in riddles.

Researchers had erected a 10-foot post to the boat dock on shore two weeks before. A partly gnawed, mangled deer leg is attached to the top. It hangs eerily against the gray sky like a stiff flag. Bronze-colored wire-mesh brushes are screwed along the sides for snagging hair samples. The brush’s bristles grabbed eagle and raven feathers, but no wolverine hair. 

After applying latex gloves, Mike discovers a few brushes with hair, most likely belonging to a pine marten, and places them into a small transparent tube. The tubes gathered from other researchers will be mailed to a genetics laboratory in Missoula, Montana. Geneticists will identify individuals, extrapolating how many reside within these boundaries, to help answer questions about this rare creature. After lag-bolting the deer leg and new brushes where needed, we retighten the wires, secure the post, and wipe the animal lure along it. The odor of the beaver's castor oil and the skunk's glands gag us.

Between the years 2002 and 2008, researchers lured wolverines into live traps using dead beavers. Gulo gulo crawled into the trap, attempting to steal the carcass, but a trap door slammed shut and locked, signaling the biologists. Researchers skied in from nearby ranger stations, attached a tranquilizer to the end of a ski pole, and jabbed the snarling wolverine. After the animal was sedated, a veterinarian surgically implanted a GPS unit into its abdominal cavity. The small device doesn’t hinder the animal and decomposes over time. Biologists once used radio collars but found they slip over wolverines’ heads because their necks are similar in size.

Chadwick relates one story about a male wolverine biologists named M3 climbing Mount Cleveland in January, the highest peak in the Glacier at 10,466 feet, in 90 minutes. Chadwick writes that “to wolverines, the landscape is flat” because they run as fast uphill as they do in the flats and take the shortest line to the highest peaks. “If wolverines have a strategy, it is to go hard and high and steep and never back down, not even from a grizzly and, least of all, from a mountain,” writes Chadwick in his book. 

Wolverines were nearly extirpated in the Lower 48 states in the early 1900s, with a few individuals left in remote mountain ranges. Federal and state wildlife agencies estimate that today approximately 300 wolverines live in the contiguous U.S. and have strongholds in Alaska and northern Canada. Roughly 100 animals live in Montana’s wild pockets, and scientists estimate that the Treasure State holds the largest wolverine population in the Lower 48. Some populations are distributed in protected biological island mountain ranges, particularly in national parks and wilderness areas in other states like Idaho, Oregon, Washington and Wyoming. A few have recently been spotted in California’s Sierra Nevada and in Utah. After this ongoing wolverine study, biologists discovered that around 40 individuals live in Glacier. 

Jeffrey P. Copeland of the Wolverine Foundation has researched Gulo gulo for over 20 years and says just because they’re hard to find doesn’t mean they’re elusive. “‘Elusive’ indicates intent to hide,” Copeland wrote in an email to Mountain Journal, “which I don’t believe wolverines do. They are simply rare and, as such, are not often observed.” 

Biologists estimate there might be a dozen or fewer wolverines in the Greater Yellowstone Ecosystem. However, these creatures have a “complex story with no definite answer,” says James Halfpenny, a renowned author, wildlife tracker and wildlife biologist. Halfpenny keeps track of wolverine sightings in Yellowstone National Park and nearby areas, and his data show subpopulations in the Crazy Mountains, the Gallatin Range and south of the park. Wolverines travel the edges of Yellowstone in the high mountains surrounding the first national park established in America. 

“The advent of cell phones and trail cameras has greatly advanced our ability to document wolverine and suggest to me that there are more wolverine in the GYE than previously thought,” Halfpenny told Mountain Journal. ”In fact, that number may also be increasing.”

In August 2022, a naturalist tour guide named Doug MacCartney observed a jaw-dropping site: a group of 13 wolverines chasing grizzly bear cubs in the Teton Wilderness just south of Yellowstone. “It was quite unbelievably phenomenal,” wrote Yellowstone Insights, the guide company MacCartney works for, in a social media post at the time.

During a multiday backpacking trip in Wyoming's Absaroka Range, MacCartney and his friends climbed a peak to honor a deceased friend. As they approached the summit, MacCartney spotted a grizzly sow with three cubs and some wolverines nearby. The bears initially showed no concern but later ran off when the wolverines appeared to chase them. "I’ve seen wolverines before, and there was no doubt in my mind what I saw," MacCartney said in an interview.

The bears ran up a steep wall while the wolverines split off, navigating the rocky cliffs. MacCartney and his group captured photos and discovered they had counted 13 different wolverines, a few of which climbed rapidly toward the summit. “Some had gained 1,000 feet and neared the summit in five or 10 minutes before we could no longer follow their moving silhouettes against the rock face,” McCartney recalled. “We were beside ourselves.  "It was clear that among the 13 were mothers with their kits." He reflected on the rarity of wolverines, estimating he has historically seen one in every 20 based on statistics. 

Wildlife advocates and environmental groups have worked to have wolverines listed under the Endangered Species Act for decades. In May 2022, a federal judge in Missoula reversed a previous decision, granting the wolverine additional ESA protections based on concerns from advocates about their populations and the impact of climate change and habitat fragmentation. The U.S. Fish and Wildlife Service debated whether the wolverine should be classified as threatened or endangered. 

According to a 2011 study on wolverine habitat, Gulo gulo prefer to den at high elevations that hold snow late into May, give birth to all-white kits, and thrive in annual summer temperatures that don’t rise above 72 F. If their habitat warms even a few degrees, subalpine firs may invade alpine regions, affecting mountain goats, their primary prey, as the rock lichens that feed goats diminish. Requiring cool temperatures and snow to remain in the alpine, wolverines have become a symbol of climate change in the Northern Rockies.

On November 29, 2023, wolverines were officially “listed as threatened” under the Endangered Species Act due to various risks, including habitat fragmentation, a warming climate and increasing winter recreation in the backcountry. Their habitat, fragmented by development, making it increasingly difficult for isolated populations to connect. Wolverines are solitary, wide-ranging mammals that often traverse state and international boundaries. Most live on public lands.

According to Chadwick’s book, wolverines inhabit northern regions, living at high elevations in summer and lower elevations in winter, but go wherever they want. Male home ranges span 300-500 square miles and commonly overlap several female territories, while females cover around 150 square miles. These animals can travel 15-40 miles in a day and have uniquely adapted, wide feet that act like snowshoes for long distances. They prefer undisturbed habitats, such as coniferous forests and tundra, away from human development. 

According to a 2021 paper by Kathleen Carroll, a wildlife ecologist and professor at Montana State University, wolverines and other wide-ranging carnivores require migration passages where habitats are interlinked through wildlife corridors or buffer zones surrounding parks. Therefore, she writes, additional development on the wildland-urban interface, or WUI, is not a strategy that benefits them.

In January 2024, Montana Fish, Wildlife and Parks informed the Department of the Interior of their intent to sue. While the case hasn’t yet appeared in court, FWP argues that the decision to list wolverines as threatened is based on "flawed, outdated science." The state contends that wolverines regularly move between Canada and the U.S. and are not isolated. However, recent research suggests this movement has decreased significantly as populations wane in southern Canada.

According to the CBC News, 90 percent of Canada’s human population lives within 100 miles of the Canada-U.S. border, fragmenting the WUI. A 2023 study published in the journal Scientific Reports shows that wolverine populations in southern Canada have decreased by 39 percent since 2011. As these populations decline, gene flow into Montana, Idaho and Washington is hindered. The southern Canadian wolverine population is becoming less viable, which threatens the long-term sustainability of wolverines in the contiguous United States since they rely on connections to northern populations.

Montana is not the only state crying wolverine; Idaho and Wyoming oppose the Endangered Species Act decision. Several industry groups, including the American Petroleum Institute, the Western Energy Alliance, and the Utility Air Regulatory Group, also express discontent. These groups are jointly part of the Trade Associations comprising 625 member companies in the oil and natural gas sector. In a 42-page 2016 document, they wrote that their companies will be “impacted by this Proposed Listing … because their businesses … emit greenhouse gases ('GHGs'), including carbon dioxide ('CO2').”

These states may no longer need to sue. On March 1, President Donald Trump signed an executive order to open 280 million acres of federal public lands to the timber industry. This could impact wolverine habitat. Fifteen days later, his administration announced plans to redefine "harm" caused to endangered species by removing habitat protections.

Mike and I found that the snow depth at the lake’s foot rapidly diminished from four feet to a depth that was unskiable. "Do you think the lake is frozen enough to hold our weight?" I ask, intimidated by the expanse of the unknown. "Previous researchers said it was ice-free just two weeks ago.”

"I hope so," Mike wishes. 

The lake's thin veneer of snow blankets the ice, covering its true depth. The ice makes sci-fi sounds, ricocheting inward and outward like a whale.

Wolf tracks deviate offshore across the ice, guiding us on a short diagonal across the frozen cove. Momentarily, we pause. Drawing upon other years, I knew that if the lake weren't frozen, we’d have to walk the snow-free trail seven miles to the head. After seeing the wolf tracks, we decide that if the ice could support a 100-pound animal, it should withstand our weight, primarily distributed on skis. We go the way of the wolf, summoning more faith with each kick and glide. 

Arriving at the cabin, we unbuckle our packs and step out of our skis. Then we unlock the place, light a fire in the woodstove and head back outside to watch the sunset. I recall a story in Chadwick’s book about how researchers flew just below a 9,000-foot summit near Logan Pass and got pings from the radio transmitter. However, they couldn’t locate the wolverine until they looked up and saw it standing above on the summit. Wolverines are known to climb peaks of all sizes and their uncanny sense of smell allows them to detect carcasses buried in avalanches miles away and 20 feet below the snow. With one of the most powerful jaws in the animal kingdom, they can crush frozen bones. They also have molars at the back of their mouths at a 90-degree angle to the others that help pulverize and crush.

We wake to a gray-bird sky. Slipping on our hiking boots, we place our ski boots inside our packs and strap skis to them. We don avalanche beacons and place shovels and probes inside our packs.

After hiking for an hour, off in the trees to our left a discordance from a storytelling of ravens shatters winter's thick air. A primal sensitivity arises as we follow wolf tracks and head off-trail to investigate the alarms. We bushwhack into the dense tangle of trees as the ravens scatter by the dozens, wheeling above and scolding us as if we’re trespassing. We pass by hair, bones and gut piles, coppering the snow. The putrescent odor of rotting flesh fills the air. In front of us, a deer lies exposed, with the rib cavity open and organs missing. The deer's eyeballs are pecked clean, leaving a vacuous stare where consciousness once stirred.

We stand amid trees that once stood straight but now splinter off several feet above the ground, while others are broken at their bases, some entirely uprooted by the heavy snow that barrelled down. A 100-yard swath of trees is mowed over by the avalanche. After inspecting the dead deer, we see another not too far away. Then another. Dozens of carcasses lay scattered under broken trees. Even with senses more alert than our own, deer could not escape an avalanche of this magnitude.

"Why are we carrying deer legs as bait?” Mike asks. “There is an all-you-can-eat buffet right here." Who knows what else could be buried here — elk, moose, mountain goats, even wolverines. Scavengers will be feeding for weeks.

Wolves, coyotes, foxes and birds have all scavenged here, and even the wily wolverine could be on the shadowed periphery. Mountain lions also investigated the mayhem and left tracks. Scavengers devour the organs first and over time will return to eat the surplus, including the bone marrow. Hiking up beyond the destruction of slain trees and bludgeoned deer toward the avalanche chute, we come over a deposited wall of snow two stories high, studded with debris. 

The avalanche had volleyed off the sawtooth mountain above, plowing over trees like a derailed train, clubbing dozens of unlucky herbivores. Trudging over a wall of snow, I spot movement as figures flee. Five grayish-tan and one black wolf scurry into standing conifers. The wolves must have been sleeping off full bellies. 

Judging by the size of the trees, this peak hasn’t released a big avalanche in decades. Winter was strange this year: Snow in the alpine came early, preceded by freezing rain making ice, then sub-zero temperatures followed by more snow. We saw the typical January thaw, causing snow to melt, become heavy, and then freeze, creating hoarfrost. More snow loading on the weak layers released the rip-roaring of the mountain’s white freight train, leaving a killing field in this valley.

We hike back silently, overwhelmed by the death and destruction. The two of us carry heavy emotions and unsettled thoughts that slide past each other. 

We both wonder how near a wolverine or a family group could be to this bountiful meat fest. There must be one or more in the vicinity of all this death. I imagine them walking in, strutting their stuff, standing up to the overstuffed wolves and taking some of the surplus. We came into this drainage and accomplished our mission, but somehow the avalanche and all the death left us both wanting to lay eyes on Gulo gulo. I wish we had more time to hide behind blinds, crouching near the destruction with cameras and audio equipment. The ghost of the forest, the wolverine, is bound to show. 

Timing is everything. Maybe that night, they came out of the darkness, manifested their bravado, and fought tooth and claw for what could be theirs. We wanted a sighting, but just knowing they’re here, loping and rambling over the hills and valleys, leaves me with a tangible wildness. 

That night, we raised whiskey glasses to life, death and everything in between, and to the phantom of the Rockies, the fearless wolverine: long may you roam.