Director John Ford’s last Western was 1964’s “Cheyenne Autumn,” his take on the 1870’s tribal attempt to escape the reservation.
The leads were non-Indians, but most of the extras were Navajos since the movie was shot at Monument Valley, within their reservation. And that was why the “Cheyenne” portrayed in the movie actually spoke Navajo. And many of their improvised comments were risqué, scatological or downright obscene.
Censors never caught it. And Native Americans still view it as an act of Indian defiance.