Absaroka-Beartooth Wilderness was created from existing National Forest lands in 1978 and is located in Montana and Wyoming, United States. The wilderness is partly in Gallatin, Custer and Shoshone National Forests and is composed of 944,000 acres (3,820 km2). The wilderness encompasses two distinct mountain ranges, namely the Beartooth and Absaroka ranges. These ranges are completely distinct geologically speaking with the Absarokas composed primarily of volcanic (or extrusive) and metamorphic rock, while the Beartooths are made up almost entirely of granitic rocks. The Absarokas are noted for their dark and craggy appearance, lush and heavily forested valleys and abundant wildlife. The highest peak in the range, located in Wyoming, is Francs Peak at 13,153 feet (4,009 m). The Beartooths are more alpine with huge treeless plateaus and the highest peak in the state of Montana (Granite Peak 12,799 feet (3,901 m)). The wilderness contains 30 peaks over 12,000 feet (3,700 m). The wilderness is an integral part of the 20-million-acre (81,000 km2) Greater Yellowstone Ecosystem and borders Yellowstone National Park.
Wilderness areas do not allow motorized or mechanical equipment including bicycles. Although camping and fishing are allowed with proper permit, no roads or buildings are constructed and there is also no logging or mining, in compliance with the 1964 Wilderness Act. Wilderness areas within National Forests and Bureau of Land Management areas also allow hunting in season.
There are 700 miles (1,100 km) of trails in the wilderness, hundreds of lakes, a few dozen streams and a similar number of small glaciers can be found in the wilderness. The forests are dominated by various species of spruce, fir and pine while in the Beartooth Mountains, due to the altitude, tundra conditions often prevail. The Beartooths have the largest unbroken area of land in excess of 10,000 feet (3,000 m) in altitude in the U.S. outside of Alaska. Animals found in the wilderness include bald eagles and yellowstone cutthroat trout and the threatened grizzly bear and lynx as well as the gray wolf.
Access to the wilderness is difficult but can be achieved via the Beartooth Highway US 212 from Red Lodge, Montana. There are also some forest access roads from the west off of US 89 south from Livingston, Montana.