Absaroka Range

The Absaroka Range

The Absaroka Range is a prominent sub-range of the Rocky Mountains, situated in the northwestern United States. This extensive mountain system stretches for approximately 150 miles (240 km) along the Montana–Wyoming border, with its widest point measuring about 75 miles (120 km) east to west. The range plays a critical role in the region's geography, serving as the eastern boundary of Yellowstone National Park and the Paradise Valley, while also defining the western edge of the Bighorn Basin. It is bordered by the Beartooth Mountains to the east and north, and the Wind River Range to the south and southwest.

Geography and Protected Lands

The Absaroka Range's rugged terrain is drained by the Yellowstone River and its tributaries, including the Bighorn River. A significant portion of the range is preserved within protected public lands. These include Yellowstone National Park itself, as well as several designated wilderness areas such as the Absaroka-Beartooth Wilderness, North Absaroka Wilderness, Teton Wilderness, and Washakie Wilderness. These protected zones span across national forests including the Bridger-Teton, Custer, Gallatin, and Shoshone National Forests, underscoring the ecological importance of the region.

Geological History

Geologically, the Absaroka Range exhibits a fascinating history, particularly related to volcanic activity. The section of the range located in Wyoming is characterized by volcanic breccia. As one moves northward across the state line, the bedrock transitions to granite and gneiss. The Absaroka Volcanic Province, covering a vast area of roughly 23,000 square kilometers in southwestern Montana and northwestern Wyoming, is a testament to this past volcanism. Extrusive igneous rocks from this province were erupted during the Eocene Epoch, between approximately 53 and 43.7 million years ago. The eroded remnants of large stratovolcanoes within this province offer geologists unique insights into volcanic structures.

Naming and Exploration

The range bears the name of the Absaroka Native People, a term derived from the Hidatsa name for the Crow people, meaning 'children of the large-beaked bird.' Early historical accounts suggest that John Colter may have been the first European American to traverse the area in 1807. Later explorers, such as Gustavus Cheyney Doane and Nathaniel P. Langford, ventured into the region, with Doane and Langford climbing Colter Peak in 1870.

Accessibility

Key transportation routes traverse or border the Absaroka Range. U.S. Highway 212, connecting Billings, Montana, to Yellowstone National Park, crosses over Beartooth Pass in the adjacent Beartooth Mountains before winding through the Absarokas. This route is typically only accessible during the summer months. Additionally, U.S. Route 14/16/20 follows the Shoshone River from Cody, Wyoming, through the range to the eastern entrance of Yellowstone National Park.