What States Do Wolverines Live In? A Current List

Wolverines have a confirmed presence in just a handful of U.S. states, and only a few of those support breeding populations. The core of wolverine range in the contiguous United States sits in Montana, Idaho, Wyoming, and Washington, with Alaska holding by far the largest population in the country. Beyond those five states, wolverines show up only as rare wanderers or, more recently, as part of deliberate reintroduction efforts. The picture is more interesting than a simple list, though, because where wolverines live today reflects a dramatic story of near-total extirpation, slow natural recolonization, and an uncertain future shaped by climate change.

The Core Four in the Lower 48

Research tracking wolverine records from the mid-1990s through the mid-2000s found that the species’ range in the contiguous United States was limited to north-central Washington, northern and central Idaho, western Montana, and northwestern Wyoming.¹ That picture has stayed broadly stable into the 2020s. Montana is the stronghold, home to the largest number of wolverines in the lower 48. Idaho and Wyoming each hold resident populations in their mountainous backcountry. Washington supports wolverines in both the northern Cascades and the northeastern corner of the state, though its population is smaller and more fragmented.

A multi-state monitoring effort using camera traps and hair snares across Idaho, Montana, Washington, and Wyoming during the winters of 2016 and 2017 confirmed wolverine detections across randomly selected survey cells in all four states.² These four states remain the only ones in the contiguous U.S. where wolverines occupy much of their historical range.³

Alaska, the Wolverine Capital

Alaska is in a different category. The state holds the vast majority of wolverines in the United States, with populations spread across Arctic tundra, boreal forest, and mountain ranges. Research on the North Slope of Alaska between 2017 and 2022 estimated population densities of roughly two to three individuals per thousand square kilometers, with males occupying enormous home ranges averaging over 2,300 square kilometers.⁴ Those density numbers were nearly ten times lower than a previous estimate for the same region, which suggests wolverines are spread thinner across the Arctic than earlier work assumed.

Unlike the lower 48, Alaska allows regulated hunting and trapping of wolverines. Aerial surveys in the National Petroleum Reserve-Alaska found that wolverine occupancy was highest in the southern and northeastern portions of the reserve, with animals preferring areas of rugged, variable terrain and well-drained soils.⁵ Managers there have proposed dividing the landscape into zones with different monitoring and harvest priorities, reflecting the uneven distribution of wolverines across Arctic Alaska.

States with Occasional Wolverines

A handful of other states have had wolverine sightings over the past two decades, but a single wandering animal does not make a population. In California, researchers photo-verified a wolverine in the Sierra Nevada in February 2008, the first confirmed sighting in the state in 86 years. DNA analysis showed it was a male whose genetics matched populations from the western Rocky Mountains, meaning it had traveled a vast distance rather than representing a surviving California population.⁶ That animal was essentially a long-distance disperser, and California has not established a breeding population since.

Colorado has also had individual wolverines detected over the years, but the state was historically listed alongside California as having only single known individuals rather than a resident population.³ That changed in late 2023 when Colorado Parks and Wildlife began actively reintroducing wolverines into the state’s high-country wilderness. The program has since released multiple animals captured from other populations, making Colorado a state to watch. Whether those animals successfully breed and establish a self-sustaining population will take years to determine.

Oregon sits in an interesting middle ground. The state has suitable high-elevation habitat, and occasional wolverine tracks or sightings have been reported, but there is no confirmed breeding population. Wolverines in the Washington Cascades could potentially disperse south into Oregon, but the species has not reestablished there in a documented, sustained way.

Where Wolverines Used to Live

Today’s range is a shadow of where wolverines once roamed. Historical records from the 1820s through the 1960s placed wolverines across the western mountains and the Great Lakes region.¹ That means states like Michigan, Wisconsin, Minnesota, and possibly parts of the Northeast once had wolverines. Michigan’s nickname, “The Wolverine State,” dates to the early 19th century, though whether it reflected actual wolverine abundance or was more of a cultural shorthand is debated by historians.

By the early 1900s, wolverines had been greatly reduced and possibly completely wiped out in the contiguous United States through trapping, poisoning campaigns targeting predators, and habitat loss. Genetic and historical evidence suggests that wolverines currently living in the lower 48 are not remnants of those old populations but instead the descendants of animals that recolonized southward from Canada during the mid-to-late 20th century.³ Utah, which once had wolverines, currently has none.

Why These States and Not Others

Wolverine distribution is not random. The species is strongly tied to cold, snowy, mountainous landscapes. Females need persistent spring snowpack deep enough to dig dens where they give birth and raise kits. Den sites tend to be placed in rugged terrain at high elevations, far from roads and human infrastructure, where snowdrifts are large enough to excavate safe, dry cavities.⁷ That requirement alone rules out the vast majority of the United States. You need mountains that hold deep snow into late spring, and those mountains need to be remote enough that wolverines are not constantly bumping into people.

In the Cascade Range of Washington, researchers modeled wolverine distribution using GPS data from ten resident adults tracked between 2008 and 2016. The results showed that climatic conditions, particularly snow and temperature, set hard limits on where wolverines can live, even in a mountain range with otherwise wild and intact habitat.⁸ This helps explain why recolonization of the Cascades from the north has been a slow, incomplete process.

Wolverines are also generalist scavengers and predators, relying heavily on carrion left by larger predators during winter. Research in Scandinavia documented wolverines feeding on moose carcasses and bird remains, with no successful hunts of large prey observed.⁹ In the Rocky Mountain states, the presence of wolves and mountain lions likely supports wolverine populations by providing a steady supply of scavengeable kills through the lean winter months. States lacking both deep snowpack and a robust large-predator community are unlikely candidates for wolverine occupancy.

The Genetic Thread Connecting Populations

The wolverines living in Montana, Idaho, Wyoming, and Washington are not isolated islands of animals. A 2024 study examining genetic connectivity across western North America found that gene flow between wolverine populations was positively associated with forest cover and negatively associated with human disturbance. Connectivity was greater in the northern part of the range, closer to Canada, than in the southern periphery. Southern populations showed lower genetic diversity and more inbreeding.¹⁰

That north-south gradient matters. The wolverines in the contiguous U.S. depend on a pipeline of genetic material flowing south from larger Canadian populations. If that pipeline gets pinched by habitat loss, roads, or development, the small southern populations could become genetically isolated and more vulnerable to inbreeding. Research on wolverines at the eastern periphery of their North American range has already found strong genetic distinctiveness from northwestern populations, with long-standing differences in DNA markers between regions.¹¹

Major highways can accelerate that fragmentation. A study of wolverines in the Canadian Rockies found that the Trans-Canada Highway, a heavily trafficked transportation corridor, was affecting gene flow and leading to demographic fragmentation of a protected population. Sex-biased dispersal across the highway meant that even when some animals crossed, the genetic consequences were uneven, eroding connectivity over time.¹² Interstate highways in the U.S. West could have similar effects, particularly I-90 in Montana and Washington, which cuts through otherwise connected mountain habitat.

Climate Change and the Shrinking Map

The list of states where wolverines live could get shorter. Because wolverines depend on persistent spring snowpack for denning, climate projections raise serious concerns. One modeling study found that under high or medium-low emissions scenarios, spring snow cover in current wolverine habitat across the contiguous U.S. is likely to decline dramatically. Summer temperatures in those same areas are projected to rise well above what wolverines currently tolerate.¹³ The researchers concluded that wolverine numbers in the lower 48, already very low, would likely decline further as habitat deteriorates.

The picture is not uniformly bleak at all elevations, though. A more recent analysis of snowpack projections specifically at wolverine denning elevations in the Rocky Mountains found that snow in April and May is likely to persist into the mid-21st century in the upper half of current denning elevations under most scenarios. The lower half of denning elevations, however, faces large declines.¹⁴ In practical terms, wolverines may be pushed higher and into smaller pockets of suitable habitat, reducing the total area that can support them even if some mountain peaks remain viable.

For states at the southern edge of wolverine range, like Wyoming, this creates a squeeze. The animals need to be high enough for snow, remote enough from people, and connected enough to other populations for genetic health. As the snowline retreats uphill, each of those conditions gets harder to meet simultaneously.

How Human Activity Shapes the Edges of Wolverine Range

It is not just climate. Within states where wolverines live, the animals actively avoid areas with high human activity, and that avoidance effectively shrinks the usable landscape. Research tracking wolverines in relation to winter recreation found that they avoided both motorized and non-motorized backcountry activity, with off-trail recreation triggering a stronger avoidance response than road-based traffic. Female wolverines showed the strongest reactions, experiencing greater indirect habitat loss from motorized winter recreation.¹⁵

Similar patterns showed up in British Columbia, where male wolverines in winter avoided helicopter skiing areas and females were negatively associated with both helicopter and backcountry skiing in mountains where winter recreation was widespread.¹⁶ The implication for U.S. states is straightforward: as backcountry skiing, snowmobiling, and heli-skiing expand into more remote terrain in Montana, Idaho, Wyoming, and Washington, the functional habitat available to wolverines contracts even when the land itself remains wild on paper. Female avoidance is especially concerning because it is the females that need secure denning habitat, and if they abandon areas due to recreation pressure, reproductive success could drop.

Tracking Wolverines Across Remote Terrain

Part of the difficulty in answering “which states have wolverines” is that wolverines are extraordinarily hard to find. They live at low densities across huge areas of rugged, inaccessible mountain terrain. A single male’s home range in Arctic Alaska can exceed 4,600 square kilometers.⁴ In the lower 48, home ranges are generally smaller but still massive by the standards of most mammals their size.

Researchers have developed methods specifically to deal with this challenge. One approach integrates motion-detection cameras with hair snags: a wolverine visits a bait station, gets photographed (its unique chest pattern serves as a natural ID), and leaves behind hair that can be genotyped for individual identification.¹⁷ In the North Cascades of Washington, researchers paired camera traps with automated scent dispensers that released attractant over the winter, boosting detection rates in areas known to hold wolverines.¹⁸

These methods are how wildlife agencies determine whether a state has wolverines and, roughly, how many. But they are expensive and labor-intensive to deploy at scale. A wolverine could be living in a state and go undetected for years simply because no one set up a camera station in the right drainage. That reality means the current list of wolverine states is a best estimate, not an absolute census. It is possible, even likely, that individual dispersing wolverines pass through states like Oregon, Nevada, or Utah without ever being documented.

Colorado’s Reintroduction Experiment

Colorado deserves its own mention because it represents a new chapter in the wolverine story. Historically, interest in establishing recovery programs existed for both the Sierra Nevada of California and the Rocky Mountains of Colorado.¹⁹ California has not moved forward with such a program, but Colorado began releasing wolverines in late 2023 as part of a state-led effort. The animals were captured from source populations and fitted with GPS collars to track their movements.

Colorado has extensive high-elevation terrain, deep snowpack in many ranges, and large wilderness areas. On paper, it looks like wolverine habitat. The question is whether a small founding population can survive, reproduce, and grow in a landscape fragmented by ski resorts, highways, and mountain towns. The state also sits at the southern edge of where snowpack is projected to hold up under climate change, so the long-term viability of a Colorado population is genuinely uncertain. If successful, Colorado would become the first state to rejoin the wolverine map through deliberate human intervention rather than natural recolonization.

Why Michigan and Minnesota Don’t Have Wolverines Anymore

People sometimes wonder why wolverines don’t still live in the Great Lakes states, given that Michigan proudly calls itself the Wolverine State. The historical record shows wolverines did occur in the Great Lakes region, with records extending from the early 1800s into the mid-20th century.¹ But the combination of intensive fur trapping, predator-control programs, and the conversion of forests to farmland eliminated them from the region entirely.

The habitat itself has also shifted. The Great Lakes states still get cold, snowy winters, but they lack the high-elevation rugged terrain that wolverines strongly prefer. Wolverine occupancy studies consistently find the animals selecting for mountainous topography with high variability in elevation.⁵ The relatively flat boreal and mixed forests of Minnesota or Michigan’s Upper Peninsula may have supported wolverines historically when the population was larger and continuous with Canadian populations, but recolonization of that habitat today would require animals to cross hundreds of miles of unsuitable lowland landscape. There is no realistic pathway for natural return.

Occasional unverified sightings surface in Minnesota or Michigan every few years, but none has been confirmed with physical evidence. Without breeding populations in nearby states and without connected mountain corridors, the Great Lakes will likely remain wolverine-free unless a reintroduction program is attempted there as well, and habitat suitability analyses suggest the odds of success would be long.