The White Buffalo (1990)

When an aging Wild Bill Hickok (Charles Bronson) finds his dreams invaded by the image of a rampaging white buffalo, he decides the only remedy is to find and kill the creature. With the help of his old friend Charlie (Jack Warden), he sets out across the snowy plains, unaware that he's not the only one looking for the fabled beast. Sioux Chief Crazy Horse (Will Sampson) has recently lost a daughter to the white buffalo, and he fears the girl's soul won't rest until he kills it.