Beaverhead Rock, Historic rock formation in Madison County, Montana, US.

Beaverhead Rock is a rock formation overlooking the Beaverhead River in Madison County, Montana, twelve miles south of Twin Bridges on Montana Highway 41. It rises 63 metres above the surrounding terrain and reaches 1,583 metres in elevation. The site is protected as Beaverhead Rock State Park and was listed on the National Register of Historic Places in 1970.

During the Lewis and Clark Expedition in 1805, Sacagawea recognized Beaverhead Rock and confirmed she was near her Shoshone homeland. This identification proved crucial because it led to trade negotiations for horses needed to continue westward.

The rock formation served the Shoshone people as a territorial landmark and helped them navigate across their traditional lands for generations. It held significance as a natural reference point embedded in their movement through the landscape.

The site is easy to reach, with a designated parking area about 14 miles south of Twin Bridges along Montana Highway 41. The location has interpretive signs and is accessible throughout the year.

Lewis's journal records that Sacagawea called the hill the Beaver's Head for its resemblance to that animal's head. The name carried over to the river below and to the mountain range beyond, so a single landmark named a whole region of southwestern Montana.