Black bears weigh from 125 to 500 pounds and usually stand less than 3 feet at the shoulder. They have curved claws that allow them to climb trees more easily than their larger cousins, grizzlies, whose claws are nearly straight. Unlike grizzlies, who generally stick to wilder country and are seldom seen by human visitors, black bears are common in forested areas across Greater Yellowstone. Like grizzlies, cougars and other asocial, people-shy species, black bears are difficult and expensive to reliably count. A black bear's diet consists mostly of vegetation, perhaps as much as 80 percent.
Grasses are a mainstay.
This means that black bears are partial to forested areas interspersed with the open meadows that grow their dinner. Bears also like bulbs, berries, and the inner bark of some trees, as well as rodents, insects and carrion. Bears are most active at night, so dusk and dawn are most likely sighting times. Most visitors don't see a black bear, but if you happen to, do not approach it except with your binoculars. They have been known to attack and kill humans.