NPS Logo

Historical Background

Survey of Historic Sites and Buildings

Suggested Reading


Lewis and Clark
Survey of
Historic Sites and Buildings

historic site Rattlesnake Cliffs

Location: Beaverhead County, on both banks of the Beaverhead River, along I-15 (U.S. 91), about 10 miles southwest of Dillon adjacent to the hamlet of Barretts.

On August 10, 1805, Lewis and three companions, heading overland to seek the Shoshonis, stopped at and named these cliffs because of the large number of rattlers in the vicinity. Five days later, Clark's boat party passed by. On the return from the Pacific in 1806, the Clark element went by the cliffs. Today they are known locally as Beaverhead Rock. In 1963, as part of the Clark Canyon Reclamation Project, a diversion dam was built in the river along the cliffs. Most of the land in the immediate vicinity is federally owned.

Rattlesnake Cliffs
Rattlesnake Cliffs from the land side. Union Pacific tracks are in the foreground. Similar cliffs rise on the opposite bank of the Jefferson River. (National Park Service (Mattison, 1958).)

Last Updated: 02-Apr-2004