It is the longest undammed river in the continental United States. Hayden Valley Hayden Valley is one of the best places in the park to view a wide variety of wildlife. It is an excellent place to look for grizzly bears, particularly in the spring and early summer when they may be preying upon newborn bison and elk calves. Large herds of bison may be viewed in the spring, early summer, and during the fall rut, which usually begins late July to early August. Coyotes can almost always be seen in the valley.
Bird life is abundant in and along the river.
A variety of shore birds may be seen in the mud flats at Alum Creek. A pair of sandhill cranes usually nests at the south end of the valley. Ducks, geese, and American white pelicans cruise the river. The valley is also an excellent place to look for bald eagles and northern harriers. Washburn Mt. Washburn is the main peak in the Washburn Range, rising 10,243 ft. above the west side of the canyon.