Adult grizzly bears have a concave face, high-humped shoulders, and curved claws. Males range from 300 to 600 pounds, and females typically weigh 200 to 400 pounds. While some grizzlies have fur that looks frosted (hence, "grizzly"), their thick fur varies in color from light brown to nearly black. Distinguishing a grizzly from a black bear can be very difficult despite the grizzly's larger size, and shorter, rounder ears.

As an omnivore, the grizzly bear eats both plants and animals. Approximately 80 to 90 percent of its diet is green vegetation, nuts, seeds, berries, and roots. Grizzlies also eat insects, and they often leave behind overturned stones and rotted logs. Most of the meat in the diet comes from animal carcasses, though the grizzly will occasionally prey on elk. In Alaska and Canada, salmon is an important food source. In the Greater Yellowstone and Northern Rockies regions, grizzlies will feed predominantly on whitebark pine seeds if given a large enough source.

In the early 1800s, an estimated 50,000 grizzly bears roamed across the western United States from the Great Plains to the Pacific coast. Today, their populations in the lower 48 states are limited to the Northern Cascades (Washington), Northern Rockies, and Greater Yellowstone Ecosystems.

Under the Endangered Species Act, the U.S. Fish and Wildlife Service listed the grizzly bear as threatened in the lower 48 states in 1975. Recovery efforts have been modestly successful in some regions. In November 2005, the U.S. Fish and Wildlife Service announced its intent to establish the Greater Yellowstone grizzly bear population as a "distinct population segment (DPS)" and to remove this DPS from the List of Threatened and Endangered Wildlife.