Vengeance is a dish served cold (1971)

After witnessing the brutal murder of his entire family by Native Americans as a child, Jeremiah Bridger becomes a merciless Indian-killer and scalp hunter. After saving the life of a beautiful Native American girl named Tune, however, the lone and silent gunman slowly reconsiders his hatred. He starts to doubt his former persuasion, that it was really Indians, who killed his family, and soon has to find out that a greedy and unscrupulous landowner usually blames Native Americans for his own crimes.