Duel at Diablo is one of the last movies in which Indians still scalp men, rape women, and subject their prisoners to cruel tortures, although some of the white men are portrayed in a pretty bad light too. One raped woman, Ellen Grange (Bibi Andersson), who ends up with a papoose, is married to Willard Grange (Dennis Weaver), who regards her as defiled. That’s fine with her, because she’d rather live with the Indian that raped her anyway. She might as well, because now that she is regarded as an outcast, some white men try to rape her as well.
James Garner’s character, Jess Remsberg, is a squaw man whose wife was scalped by a white man, and he is out for revenge. That man turns out to be Willard, who wanted to get even for what had happened to his wife.
Sydney Poitier is also in this movie. Since race plays such a large role in this movie, we expect his race to also be a factor, but no one mentions it or reacts to it. Other than that, it’s the cavalry versus the Apaches, and what a slaughter! Not only do men die left and right, but many are wounded and crippled. Even the horses get killed.
Perhaps as a step toward the apologist Westerns of the seventies, there is reference to the way the Apaches are mistreated on the reservation at San Carlos. As the Apache prisoners are led away by the cavalry at the end of the movie, Jess makes a remark to the effect that the Apaches will probably go off the reservation again, because they have no reason not to.