When a party of Lakota Sioux raiders attacked a small wagon train of Shoshone, white and mixed-race people in 1868, eight-months-pregnant Woman Dress Lamoreaux stopped the skirmish when she climbed from a wagon and threatened the attackers with drastic consequences from her brother, Gall—their war chief—if they continued the fight.

Westbound emigrants in the Sweetwater Valley on the Oregon Trail saw the distinctive gunsight notch of Split Rock and “steered to this cliff with a steadiness that was astonishing,” according to one diarist. The landmark stands 11 miles west of Devil’s Gate and about 75 miles east of South Pass.