Gunther says grizzly bears are active primarily during the night and during early morning hours. In the warm afternoon, grizzlies tend to bed down, he says. So to see a grizzly, use a spotting scope and scout large, open meadows just after sunrise and just before sunset. Grizzly bears are most commonly seen along the road corridor from Tower south through Canyon, Lake, and Fishing Bridge, to the East entrance of the park. They are also commonly observed in the northwest corner of the park.
Black bears are more active during daytime.
Look for black bears around the northern range of the park, Gunther says. They can often be observed near the road corridor from Mammoth east through Tower to the park's Northeast entrance. Black bears are also commonly observed near Old Faithful, Madison and Canyon areas, as well as near the Bechler region in the southwest corner of Yellowstone. Grizzly bears feed on bison carcasses and elk calves, especially in the spring. Their predation on elk calves continues until mid-summer.