Yellowstone National Park is home to two species of bears: grizzly bears and black bears. Both roam the park’s forests, meadows, and river valleys, but they differ in size, appearance, diet, and where you’re most likely to spot them.
Grizzly Bears
Grizzly bears are the larger and more iconic of Yellowstone’s two bear species. Adults typically weigh between 300 and 700 pounds, with males on the bigger end. The easiest way to identify a grizzly is by the distinctive muscular hump on its shoulders, which powers its front legs for digging. Their face has a concave, “dished” profile between the eyes and snout, and their ears are short and rounded. Their front claws are long, slightly curved, and measure 2 to 4 inches depending on how much digging the bear does.
The grizzly population in the Greater Yellowstone Ecosystem has made a remarkable recovery. When they were listed as threatened under the Endangered Species Act in 1975, their numbers had dropped dangerously low. By 1984, an estimated 270 grizzlies remained. That number has since increased nearly fourfold to roughly 1,030 bears as of 2023. Despite this recovery, Yellowstone’s grizzlies still retain threatened status under federal law. In early 2025, the U.S. Fish and Wildlife Service denied petitions from Montana and Wyoming to delist the Greater Yellowstone grizzly population, keeping federal protections in place.
Grizzlies are true omnivores with a diet that shifts dramatically by season. In spring, they feed on elk and bison calves, winter-killed carcasses, and the roots and bulbs of plants like yampa and oniongrass. Summer brings spawning cutthroat trout in Yellowstone’s streams, and bears travel to remote high-altitude talus slopes to gorge on army cutworm moths, which pack more calories per gram (7.9 kcal/g) than any other food grizzlies eat. In fall, whitebark pine seeds become a critical fat source to fuel hibernation. Bears move through their home ranges following this seasonal buffet, visiting elk calving areas, spawning streams, moth aggregation sites, and pine forests in a predictable annual pattern. In total, researchers have documented grizzlies eating at least 36 species of invertebrates alone, including ants, yellow jackets, and earthworms.
In recent decades, some of these high-calorie food sources have become less reliable. Cutthroat trout populations have declined, and whitebark pine trees have suffered from disease and beetle infestations. Only about two-thirds of grizzlies in the ecosystem even have access to whitebark pine. These shifts have pushed bears to rely more heavily on other foods, particularly meat from large animals like bison and elk.
Black Bears
American black bears are Yellowstone’s other bear species, and despite the name, their fur can range from jet black to cinnamon brown, which sometimes causes confusion with grizzlies. The key differences are structural. Black bears lack the shoulder hump, have a straight facial profile from forehead to nose, and sport taller, more oval-shaped ears that look prominent on their head. Their front claws are shorter (under 2 inches) and more tightly curved, built for climbing trees rather than digging.
Black bears are smaller than grizzlies, with adults generally weighing 200 to 400 pounds. They tend to favor forested areas, which provide food, thermal cover, and the security of climbable trees. Research in northern Yellowstone found that black bear density was significantly higher in forested areas compared to open meadows. Female black bears were more densely concentrated than males. The northern range of Yellowstone supports roughly 20 black bears per 100 square kilometers, one of the highest densities recorded anywhere in the northern Rocky Mountains, where other areas typically see 6 to 12 bears per 100 square kilometers.
Black bears eat many of the same foods as grizzlies, including berries, grasses, insects, and occasionally elk calves, but they’re generally less predatory and more reliant on vegetation and smaller food sources. Their ability to climb trees gives them access to food and escape routes that grizzlies can’t easily reach.
Where to See Each Species
Grizzly bears are most commonly spotted in Lamar Valley, Hayden Valley, Swan Lake Flats, Gardiners Hole, Dunraven Pass, and the wet meadows along the East Entrance Road between Fishing Bridge and the park’s east boundary. These open valleys and meadows are where grizzlies forage and where visibility is best.
Black bears show up more frequently in the northern part of the park, particularly along the road between Elk Creek and Tower Falls, and from Mammoth Hot Springs north to Indian Creek. These routes wind through the forested habitat black bears prefer. Early morning and evening are the most active feeding times for both species.
Staying Safe Around Bears
Yellowstone requires visitors to stay at least 100 yards (91 meters) from bears at all times. Approaching closer is illegal and can result in fines, injury, or worse. This applies everywhere in the park, whether you’re on a boardwalk, a trail, or watching from the road.
Bear spray is the single most important safety tool you can carry. Every person in your group should have their own canister in a waist or chest holster where it’s immediately accessible, not buried in a backpack. In areas with poor visibility or thick vegetation, carry it in your hand with the safety clip ready to remove. If a bear charges, spray when it’s 30 to 60 feet away, aiming slightly downward and adjusting for wind. Keep spraying until the bear turns away. Bear spray is not a repellent, so never apply it to your body, clothing, or gear.
If a bear approaches out of curiosity, grab your belongings (especially food) and walk to a car or building. Do not run. If retreating isn’t possible, group up with other people, make yourselves look large, and yell. If a curious or predatory bear actually makes contact, fight back aggressively. Bear spray can be rented at Canyon Village near the Visitor Education Center and at Old Faithful if you don’t want to purchase a canister.