Congress designated the Absaroka-Beartooth Wilderness in 1975. Over 920,000 acres of the wilderness area coincide with Montana's Gallatin, Custer, and Shoshone national forests. Just over 23,000 acres of the wilderness lies in Wyoming. The Absaroka-Beartooth, just north of Yellowsyone National Park, is considered an integral part of the 20-million-acre Greater Yellowstone Ecosystem.
The wilderness consists of two distinct mountain ranges. The Absaroka, named for the Crow people, is the more fertile range, densely forested with spruce, fir, and pine, and frequented by bighorn sheep, mountain goats, elk, deer, moose, marmots, coyotes, wolves, black bears, grizzlies, and Yellowstone cutthroat trout. Fauna thins out in the higher-elevation Beartooth Range, which features treeless plateaus, steep canyons, small alpine lakes, and Montana's highest point: 12,799-foot Granite Peak.
The Absaroka-Beartooth Wilderness's 700-mile trail system is most often accessed via the Beartooth Highway, US 212, from Red Lodge or by forest access roads off of US 89 south of Livingston.