Grizzly Bear is the common name for North American populations of the Brown bear, famous for its prominent shoulder hump, long digging claws, and powerful build. It lives across parts of Alaska, western Canada, and the northwestern United States, occupying habitats from coastal forests to alpine meadows.
Notable for its ecological role as an omnivorous “ecosystem engineer,” the grizzly moves nutrients through landscapes by digging, grazing, and scavenging. It is also one of the continent’s most studied large mammals, especially in places like Yellowstone National Park.
The grizzly is a subspecies of the brown bear, with the scientific name Ursus arctos horribilis. In Alaska, very large coastal brown bears include populations often discussed separately, such as the Kodiak bear, though all remain within Ursus arctos.
Adult grizzlies vary greatly by region and food supply, typically weighing about 180–360 kg (400–800 lb) for males and 130–200 kg (290–440 lb) for females. Body length commonly falls around 1.7–2.4 m (5.6–7.9 ft) from nose to rump, with a shoulder height near 0.9–1.1 m (3.0–3.6 ft) when standing on all fours.
The hallmark shoulder hump is a mass of muscle that powers forelimb strength for digging roots, rodents, and dens. Fur ranges from blond to dark brown, often “grizzled” with pale tips, and the front claws are usually 5–10 cm (2–4 in) long—built more for excavation than climbing.
In the wild, grizzlies often live about 20–25 years, while well-managed captivity can reach roughly 30–35 years. Compared with the American black bear, grizzlies tend to have a concave facial profile, smaller ears, and a heavier forequarter build.
Grizzly bears occupy a broad range of ecosystems, including boreal forest, coastal rainforest edges, river valleys, subalpine slopes, and Arctic tundra. Today, their strongest populations occur in Alaska and western Canada, with smaller, more fragmented groups in the contiguous United States.
Historically, grizzlies ranged from Alaska to northern Mexico and from the Pacific Coast to the Great Plains. In the lower 48 states, the largest remaining strongholds include the Greater Yellowstone and Northern Continental Divide ecosystems, where management focuses on connectivity between habitat blocks.
Grizzlies are omnivores with highly seasonal diets: spring often emphasizes emerging grasses, sedges, and winter-killed carcasses, while summer adds berries, roots, insects, and small mammals. In many regions, autumn “hyperphagia” drives intense feeding to build fat reserves for winter, with individuals consuming tens of thousands of calories per day when foods peak.
Where available, spawning runs of Salmon can transform bear ecology, supporting higher densities and larger body sizes in coastal systems. Grizzlies can sprint at roughly 50–55 km/h (31–34 mph) over short distances, a burst speed that helps in brief chases or defensive charges.
Unlike lions or wolves, grizzlies are mostly solitary outside of mating season and concentrated food sources, though multiple bears may tolerate one another at rich fishing sites. They den for winter, and depending on latitude and weather, hibernation can last about 5–7 months, with pregnant females giving birth to 1–3 cubs in the den.
As a species (Ursus arctos), the brown bear is listed as Least Concern on the IUCN Red List (assessment year varies by region and update cycle), but that global label masks sharp local differences. Some grizzly populations are robust, while others remain small, isolated, or politically contentious in management.
Across North America, best-available estimates commonly place the total at roughly 55,000–70,000 grizzlies, with the great majority in Alaska and Canada; the contiguous U.S. holds only a small fraction of that total. Primary threats include habitat fragmentation, mortality associated with roads and development, illegal killing, and food-conditioning around people.
One of the most persistent challenges is Human–wildlife conflict, especially where bears access garbage, livestock feed, orchards, or hunter-killed carcasses. Conservation efforts emphasize securing attractants, maintaining travel corridors, reducing road impacts, and using nonlethal deterrents—alongside carefully regulated hunting where populations can sustain it.
In North America, “grizzly bear” usually refers to inland populations of the brown bear, while “brown bear” can include both grizzlies and larger coastal forms. All are generally classified within Ursus arctos, with regional size differences driven mainly by food availability.
Grizzlies typically have a pronounced shoulder hump, longer front claws, and a more concave facial profile, while black bears more often show a straighter face and taller ears. Color is unreliable, because both species can range from blond to dark brown.
Increase distance calmly, avoid running, and speak in a steady voice while backing away to reduce surprise and tension. In many regions, carrying bear spray and storing food properly are among the most effective ways to prevent dangerous encounters.