The expedition encountered more and more dangers the farther west they traveled. Rattlesnakes and grizzly bears. River rapids and hailstorms.
By mid-August, Lewis realized that winter would soon be upon them. He pressed forward and met the Shoshone, who had the horses the expedition needed. The tribe wanted to move east to hunt bison.
Using sign language, Lewis persuaded the Shoshone chief, Cameahwait, to wait for the rest of the expedition. He said that the group included a Shoshone woman and a "man who was black and had short curling hair."
The chief agreed, and he and his men also found York to be "big medicine." Among the Shoshone and other tribes, men who had fought in battle used charcoal on their faces. As York was all black, he was thought to be a great warrior, more powerful than the white men with whom he traveled.