At the end of the American Civil War, Ty O'Malley sets off to pursue his dream of becoming a mountain man. But construction of the transcontinental railroad and the white man’s need to eliminate the buffalo create Indian uprisings. Ty befriends Rocky, a tough mountain man in search of his lost love, Evening Star. Ty is given the Sioux name Wicasa Tuwe Mani kici Sumanita Taka, which means Man Who Walks with Wolf. Ty establishes a relationship that will last a lifetime with Chief Running Horse.