Burt Reynolds plays a half-breed (half-white, half Yaqui Indian) native American in this movie. Reynolds had previously played a Navajo Indian in the western movie Navajo Joe. Reynolds is of part Cherokee Indian descent.
Though this movie has often been called a "spaghetti western", it actually isn't. That term is applied to westerns that were filmed by European companies (usually Italian), with a European (usually Italian) cast and crew and shot in Spain, because its terrain closely resembles the northeast Mexico/southwest US area. Although this film was shot in Spain, it was filmed by an American studio (20th Century-Fox) with an American director, producer, writers and mostly American crew. Star Burt Reynolds' previous film, Navajo Joe, would be properly regarded as a "spaghetti western", but not this one.
Part Cherokee Indian, Burt Reynolds plays a Yaqui Indian in this movie. Prior to the making of this film, Reynolds had played characters of Indian descent in two productions of television series. The first was as the half-breed blacksmith Quint Asper in _"Gunsmoke (1955)"_ whilst the other was as the New York DA's office cop Detective Lieutenant John Hawk, a full blooded Iroquois Indian, in Hawk.
In both of the 1960s big screen westerns where Burt Reynolds plays an Indian character, he is called Joe. He is Navajo Joe in Navajo Joe and Yaqui Joe Herrera in 100 Rifles.
The trivia items below may give away important plot points.
This movie was apparently one of the first movies to feature a sex scene between people of different races. They were African-American Jim Brown and white American Raquel Welch.