Six U.S. States With the Largest Beaver Populations

Across North America, the beaver has quietly staged one of the continent’s most significant wildlife recoveries, turning streams and wetlands into intricate networks of ponds and dams. While no agency keeps a precise census of every colony, biologists and land managers consistently point to a handful of U.S. states where this ecosystem engineer is especially abundant. Looking at habitat, history and current management, six states stand out for hosting some of the largest and most resilient beaver populations in the country.

From the icy rivers of Alaska to the forested lakes of Minnesota and New York, these strongholds reveal how geography and policy combine to shape where beavers thrive. They also show how a species once trapped nearly to extinction has become central to debates over water, wildfire resilience and coexistence with people.

Why exact beaver counts are elusive

Before ranking any state, it helps to understand why no one can say exactly how many beavers live within a given border. A detailed discussion of population tracking notes that wildlife agencies do not conduct full beaver censuses, since the animals live in remote wetlands, move often and build structures that can be hard to spot under dense vegetation or ice. One analysis bluntly concludes that “no one knows because no one counts them,” adding that this is “pretty much true for every state,” a point illustrated in a review of how many beavers might live in each state that highlights the limits of current estimates through How.

Instead of raw head counts, researchers rely on indirect indicators such as dam surveys, aerial imagery and family group densities. A classic technical report on beaver ecology lists “Numbers of Beavers per Pamity in Various Areas” and gives an “Average No./ Family” for several regions, including “41” for Alaska, “Montana 4.1” and “Newfoundland 42,” all summarized under the heading “Numbers of Beavers per Pamity in Various Areas. Area. Average No./ Family. 41. Alaska. Montana 4.1 Newfoundland 42 Adirondacks, NY,” as shown in a federal attachment that compiles these Numbers of Beavers.

Modern work often focuses on structures rather than animals. A recent “groundbreaking beaver study” in the Southwest, for example, relied on a large-scale survey of dams that found many more on private land than public. The researcher identified as Darr explained that this pattern “allows the beavers to still flourish and be safe” on lands where access is limited, while the study’s authors admitted that the mix of public and private parcels “makes it nearly impossible to survey accurately,” as described in coverage of how that survey was conducted.

At the continental scale, historical estimates show just how far the species has rebounded. A wildlife fact sheet from Nevada notes under “Fun Facts” that before Europeans colonized North America, the Beaver population was estimated to be “100 to 200 m” individuals, with current numbers closer to an “estimated 15 million individuals today,” according to the Fun Facts section. A separate review of population status gives an even broader historical range, stating that the North American beaver, Castor canadensis, once reached an estimated maximum of “60, 400 m” individuals across the continent, a figure cited in an overview labeled “Sep 22, 2015, North American beaver, Castor canadensis, reached an estimated maximum population of 60-400 million individuals,” which appears in a Sep analysis.

Given these uncertainties, any list of states with the “largest” beaver populations rests on a mix of habitat extent, historical abundance and current management rather than precise tallies. The six states below consistently emerge as strongholds when those factors are combined.

Alaska: a northern powerhouse of beaver habitat

Alaska’s vast size and relatively intact river systems give it a strong claim to hosting one of the largest beaver populations in the United States. The state covers a huge swath of boreal forest, tundra and wetland, all prime territory for lodges and dams. A general overview of Alaska highlights its extensive interior rivers and lake networks, which provide the slow-moving water and willow stands that beavers favor.

The historical density figures in the “Numbers of Beavers per Pamity in Various Areas” table support that picture. In that document, Alaska appears with an “Average No./ Family. 41,” which suggests a relatively high number of animals per family unit in the study’s sample of “Various Areas,” as recorded in the federal attachment on beaver Various Areas. While those figures are dated and do not translate directly into a statewide population, they align with field observations that beavers occupy a wide range of Alaskan watersheds.

Alaska’s climate also plays a role. In the far north, beavers must withstand long winters, thick ice and short growing seasons. A feature from the U.S. Fish and Wildlife Service notes that when painting a picture of the fauna of the pre-colonial North American West, observers often imagine bison and wolves, but beavers also shaped rivers and wetlands, even in some of the coldest parts of the year. That account of how beavers work to improve habitat across the North American West mirrors what biologists see in Alaska’s subarctic landscapes.

Current conflicts in Alaska tend to center on infrastructure and flooding rather than scarcity. As in many northern states, transportation departments and landowners focus on managing culverts and roads where dams back up water. There is little sign that the state’s overall beaver numbers are in trouble, which keeps Alaska near the top of any list of beaver strongholds.

Oregon: the Beaver State lives up to its name

No state leans into its beaver identity more than Oregon. The animal is embedded in its nickname, its university mascot and its economic history, and it remains widespread on rivers from the Coast Range to the Cascades. Basic reference material on Oregon notes the state’s extensive network of forests and waterways, which create ideal conditions for beaver colonies.

A conservation profile explains that in addition to being the largest North American rodent, the beaver is Oregon’s state animal. Under a section titled “About,” the description emphasizes that this North American species is central to local ecology and culture, detailing how beavers use scent to mark food and recognize family members and describing their role in shaping riparian zones, as laid out in the About section.

Historically, the species helped drive the region’s economy. One account of settlement notes that while Oregon was being settled the fur trade was a staple to the economy, earning Oregon the nickname “Oregon the Beaver state.” That same discussion explains that while beaver numbers crashed under intense trapping, they have since recolonized much of Oregon’s waterways and riparian areas, a story traced in the passage that begins “While Oregon was being settled the fur trade was a staple to the economy, earning Oregon the nickname ‘Oregon the Beaver state.’ While beavers were nearly wiped out, they have returned to many of Oregon’s waterways and riparian areas,” as summarized under While Oregon.

The nickname itself has been embraced by advocates who highlight the animal’s role in desert watersheds. A feature on Oregon’s high desert explains that “Oregon: The Beaver State” is more than a slogan, and that nearly half of Oregon is high desert where beavers can still transform arid valleys into chains of ponds and wetlands. That piece, published by the Oregon Natural Desert Association, invites readers to “Discover Oregon’s High Desert” and is framed under “Oregon: The Beaver State – Oregon Natural Desert Association. Discover Oregon’s High Desert. Did you know that nearly half of Oregon is high desert?” as described in the Discover Oregon overview.

Another related piece notes that “You may have heard Oregon referred to as the ‘Beaver State.’ The American Beaver, Castor canadensis, is Oregon’s official state animal and the Oregon State University mascot,” language that ties The American Beaver and Castor directly to state identity, as highlighted in the Beaver State description.

With abundant habitat, a long cultural connection and active advocacy around beaver-based restoration, Oregon remains one of the most beaver-rich states, even if no one can pin down an exact number of colonies.

Washington: a hub of beaver-based restoration

Neighboring Washington combines a wet climate, diverse landscapes and a growing embrace of “beaver-powered” restoration. General reference material on Washington highlights the state’s mix of coastal rainforest, interior plateau and mountain watersheds, all of which host beaver colonies.

In recent years, King County has become a focal point for this work. A video feature explains that King County is updating its approach to Habitat restoration in order to capitalize on the unique talent of recovering wildlife, with beavers at the center of that strategy. The segment, presented in early Jun, describes how county staff are experimenting with relocation, flow devices and other tools so that beavers can build dams that slow water, store snowmelt and create rearing habitat for salmon, a story framed in a piece titled “Here’s why beaver populations are back on the rise” that highlights King County.

Statewide, Washington’s mix of private timberland and public forest creates both opportunities and conflicts. On one hand, beavers help retain moisture in headwater streams, which can buffer forests against drought and wildfire. On the other, their dams can flood roads, culverts and pasture. Agencies increasingly treat beavers as partners in climate adaptation rather than pests to be removed, which has likely helped stabilize or increase populations in many watersheds.

Because Washington bridges the wet Pacific coast and the drier interior, its beaver populations also illustrate how the species can persist in both rainforest creeks and semi-arid valleys. That ecological range, combined with active restoration, keeps Washington on any short list of beaver-rich states.

Minnesota and Michigan: strongholds in the Great Lakes region

The upper Midwest, with its dense networks of lakes and rivers, has long supported large numbers of beavers. Minnesota and Michigan stand out in this region for their extensive forest cover and documented colony densities.

In Minnesota, the Department of Natural Resources notes that within the beaver’s range there are “0.6 beaver colonies (less than one) per river mile.” This figure appears under a section titled “Population and management” and gives a sense of how widely distributed colonies are along streams. The same fact sheet explains that during the winter, a beaver relies on stored food and well-insulated lodges to survive, information presented under the heading “Population and management In its range, there are 0.6 beaver colonies (less than one) per river mile. During the winter, a beaver …,” as summarized in the Population and section.

Basic overviews of Minnesota emphasize its identity as the “Land of 10,000 Lakes,” and that abundance of water, combined with extensive aspen and willow stands, explains why beavers are common across much of the state. Trapping seasons and nuisance control programs are designed to keep populations compatible with forestry and infrastructure while maintaining healthy numbers.

Michigan offers a similar story. With two peninsulas ringed by the Great Lakes and laced with rivers, it provides ideal habitat for beavers in both lowland swamps and upland streams. Reference material on Michigan highlights its mix of forest and wetland, and state wildlife agencies manage beaver through regulated trapping, relocation and site-specific mitigation.