Where in the World are the Wolverines?


November 12, 2021

By Guest Blogger Beth Glosten, WNPF Board of Directors

The wolverine is one of the most elusive and fascinating carnivores of the North Cascades. Washington’s National Park Fund was joined by Ranger Merrisa Bluestein of North Cascades National Park for a Virtual Field Trip in July 2020 where we were introduced to this critter and all its unique characteristics – and we learned a lot.

First, they are quite rare. There are less than 36 (!) wolverines in Washington state, and fewer than 300 in the lower 48 states. Why so few? For one, their population was reduced dramatically in the early 1900s from trapping – they have an amazingly thick and warm coat – and poisoning, as they are clever and can remove bait from traps for other animals, angering hunters.

Get to Know the Wolverine

Wolverines face survival stress from climate change. Rising temperatures have affected the durability of their habitat – the remote and rugged snowy alpine and subalpine areas. Females depend on persistent snowpack to maintain their dens deep in the snow. These dens house and protect their white kits from February to May. If temperatures warm, they no longer have the safety of their den. Wolverines are scavengers and, with their keen sense of smell, can locate dead animals in the snow. They form caches of food in the snow, using it for refrigeration. No snowpack, no stored food.


Wolverine Family at Mount Rainier National Park (photo by Cascades Carnivore Project/NPS)

Human recreation also affects wolverines. Disturbances from backcountry adventurers and snowmobilers in the winter risk interfering with the denning behavior of female wolverines.

Finally, wolverines have a wide area in which they travel to find food and mates. One animal might cover hundreds of square miles in less than a year. Highways that cross their territory, such as SR 20 through North Cascades National Park, and Interstate 90 across the whole of the state, place both a barrier and a risk to accessing this territory.

However, starting in 1999 with the upgrading of I-90 across the Cascades, the Washington Department of Transportation in conjunction with the US Forest Service has built wildlife crossings along the highway. Culverts have been replaced with open areas beneath the roadway to allow streams and wildlife to cross under the road. There is also a 150-foot overpass: elk, deer, coyote, bobcat, mountain lions, raccoons, pine martens, and fishers have been seen using the bridge. No documented wolverines on the overpass yet, but in 2018, two wolverine kits were documented south of I-90.

These critters are hardy! They are stocky and muscular with a dark brown coat flecked with tan. They thrive in rugged, remote, snowy alpine and subalpine regions. Their location makes them challenging to study, but if caught on camera, each has a unique pattern of dark and white chest hair that makes them identifiable. Their large snowshoe-like paws and sharp crampon-like claws both allow them to travel over the surface of deep snow and ascend trees and icy slopes. Merrisa provided this quote from the book “The Wolverine Way,” by Douglas Chadwick:

If Wolverines have a strategy, it’s this: go high, and hard and steep and never back down. Not even from the biggest grizzly and least of all from a mountain. Climb everything… eat everybody, alive, dead, long dead, moose, mouse, fox, frog, its still warm heart, or frozen bones.

When I think of wolverines, my mind conjures up an image of a fierce dog-sized animal. While they are courageous and will go after animals larger than themselves, Merissa made it clear that they will run from humans. The chances of seeing one of these elusive animals is very, very low.

Several local not-for-profits study our Pacific Northwest wolverines. If you are interested in getting involved, reach out to Cascade Carnivore ProjectCascades Wolverine Project, and Conservation Northwest.

Wolverine showing off its claws
The furry underside of a wolverine showing the stomach, bottom of the paws and claws as seen from the camera stand (photo by NPS/Cascades Carnivore Project)

An Update on Wolverine Populations in Washington

Washington’s National Park Fund has played a role in studying these elusive creatures by funding wildlife monitoring research projects, and this year we were all excited to hear some very good news on the wolverine population front.

In August 2021, Mount Rainier National Park documented two new wolverine kits! This is the second litter of a female wolverine identified in the park in 2019. Her two litters comprise two of the three wolverine sitings in the South Cascades in the last 100 years. All are hopeful that this bodes well for the species to thrive in this area. You can learn more about this exciting finding in the park’s press release.

Still Curious for More?

You can find Merissa’s presentation and enjoy more photos of wolverines and North Cascades National Park on our Virtual Field Trips page.