During the mid-19th century, in what is now South Dakota, Crazy Horse (Michael Greyeyes) of the Oglala Sioux rises to prominence in his tribe. He falls in love with the married Black Buffalo Woman (Irene Bedard), and uses his trance-like visions to help his uncle, Chief Red Cloud (Wes Studi), and his people fight for independence against the advancing American forces. Eventually, they defeat General Custer (Peter Horton) and his men, but they then must face the reality of Westward expansion.