French trappers found the area in the late 18th century peopled by Native American tribes such as the Blackfoot, Northern Cheyenne, Sioux, Assiniboine, Gros Ventre (Atsina), Crow, Plains Cree and Plains Ojibwa.
The Lewis and Clark Expedition passed through the Breaks in 1805 and were the first to document the region through notes and drawings, and their sighting and documentation of bighorn sheep in the Breaks region was the first time this species was recorded in North America by white explorers.