Northern Yellowstone sustains one of the largest and most diverse populations of free-roaming wildlife seen anywhere on earth.
It is often called "America's Serengeti." About half of the approximately 30,000 elk that summer in the park spend the winter here on the northern range. Elevations here are lower, and the area receives less moisture than elsewhere in the park. During winter, wind and sun keep the ridge tops and south-facing slopes relatively free of snow, allowing animals easier access to forage.
Most large grazing animals in Yellowstone, especially elk, are migratory. As the days lengthen in spring, the warm breezes melt the snow and the hills and ridges "green up." The animals follow the receding snow to higher elevations, eating the new, succulent grasses and forbs that are highly nutritious. Following a summer in the high country, the animals move back to lower elevations in the fall.
Wildlife viewing in Yellowstone is popular at any time of year. But, remember, the animals you see here are wild. You will see more of an animal's natural behavior if you keep your distance. Stay at least 25 yards away from bison, elk, bighorn sheep, deer, moose, coyotes, or other wildlife (and at least 100 yards away from bears). Use your vehicle as a "blind" and view wildlife safely from it.