Bison, bears, coyotes, wolves, and birds of prey all call Hayden Valley home almost year-round. Once part of Yellowstone Lake, the broad valley now contains peaceful meadows, rolling hills, and a serene stretch of the Yellowstone River. There are multiple turnouts and picnic areas on this 16-mile drive. Ask a ranger about "Grizzly Overlook," an unofficial site where wildlife watchers, including NPS rangers with spotting scopes for the public to use, congregate in summer. North of Mud Volcano are 11 unsigned turnouts. Look for the telltale timber railings, and be prepared to get caught in a traffic-stopping "bison jam" along the way.