The North American brown bear (Ursus arctos) is a massive apex predator whose distribution across the United States is highly restricted today. While the species includes the large coastal bears of Alaska, the term “grizzly bear” is commonly used for the inland subspecies (Ursus arctos horribilis) found in the contiguous U.S.
States with Current Brown Bear Populations
Brown bears currently inhabit five U.S. states, with the vast majority residing in Alaska. Alaska is home to approximately 30,000 brown bears, representing nearly 98% of the entire American population. These bears thrive in diverse Alaskan habitats, from coastal regions where they feed heavily on salmon to interior mountain ranges and tundra.
The remaining population of approximately 2,000 brown bears is scattered across the contiguous Lower 48 states. These bears are found in four Western states: Montana, Wyoming, Idaho, and Washington. Their presence is isolated to remote, rugged mountain ecosystems that offer the necessary large, intact wilderness areas.
Key Habitats and Recovery Zones
The brown bear population in the contiguous United States is listed as threatened under the Endangered Species Act (ESA), necessitating focused conservation efforts. Management is centered on six federally designated Grizzly Bear Recovery Zones, which are specific geographic areas established by the U.S. Fish and Wildlife Service. The most robust populations are concentrated in the Greater Yellowstone Ecosystem (GYE) and the Northern Continental Divide Ecosystem (NCDE).
The GYE population occupies areas spanning northwestern Wyoming, eastern Idaho, and southwestern Montana, with its core in Yellowstone National Park. The NCDE, which includes Glacier National Park, is situated primarily in Montana and extends into northern Idaho. Other designated recovery zones include the Cabinet-Yaak and Selkirk ecosystems (Montana and Idaho), the North Cascades (Washington), and the Bitterroot ecosystem (Idaho and Montana).
The Historical Distribution of Brown Bears
The current limited distribution stands in sharp contrast to the brown bear’s extensive historical range across North America. Before European settlement, the grizzly bear roamed across much of the western contiguous United States, from the Pacific Coast to the Great Plains. Historical records indicate that grizzly bears were present in at least 18 states, including California, Oregon, Utah, Colorado, Arizona, New Mexico, and the Dakotas.
This extirpation, or local extinction, from the majority of their range was largely complete by the early 20th century. Expansion of ranching and agriculture, habitat fragmentation, and widespread hunting led to the species’ massive decline. California, for instance, features the grizzly bear prominently on its state flag, yet the last known wild brown bear there was killed in 1922.