His initial work was in the Don Shebib-directed coming-of-age film, Rip-Off, in 1971. In 1981, he did voices for the animated film Heavy Metal. During the late 1990s he had major roles in Black Robe (as Chomina), Free Willy and its sequels (as Randolph Johnson), Iron Will (Ned Dodd), True Heart (Khonanesta), and TV film Crazy Horse (Sitting Bull). He went on to star as Chief Powhatan in Terrence Malick's 2005 film The New World. He also had roles in Disney's Eight Below and the doco within a film The Green Chain (2007). In 2011, he appeared in two episodes of the television series Stargate Universe as Yaozu. His favorite role was that of Sitting Bull in the film Crazy Horse, a character he reprised in the film version of the Dee Brown bestseller Bury My Heart at Wounded Knee, for which he received an Emmy nomination. He also starred in Dreamkeeper (2003) as Pete Chasing Horse.