- California Doubling: The film, set in Mexico, was shot in Spain.
- Deleted Scene: Akim Tamiroff shot scenes for the film as one General Romero, but these ended up being cut from the film.
- Hostility on the Set:
- Jim Brown and Raquel Welch clashed during filming; Welch confirmed the tension while saying that she didn't know why it happened, saying that it was "ambiguous as hell", while Brown later said that he wanted to avoid "any suggestion that I was coming on to her" and got misinterpreted.
- The above eventually took its toll on Burt Reynolds, who had to act as referee between the two, and as a result him and Welch had a falling out. Three years later, when they both starred in Fuzz, they only did the picture after one of them was reassured that they would not have to appear in any scenes with the other (although there are conflicting sources as to whether it was Reynolds or Welch who asked this). They would eventually reconcile in 1982 when the producers of Cannery Row fired Welch claiming she was unprofessional and replaced her with Debra Winger, and in the ensuing lawsuit by Welch (which she ultimately won), Reynolds testified on her behalf, stating that in his experiences filming with her "she was always on time well-prepared and thoroughly professional."
- Old Shame: Burt Reynolds tended to lampoon the movie when looking back at it, saying of the concept of him playing a half-Native American, half-white man, "I make it seem like the other 'half' of the guy is from Alabama," and that between it and that "Raquel [Welch] had a Spanish accent that sounded like a cross between Carmen Miranda and Zasu Pitts," "it just didn't work." (Though he also acknowledged Welch as "one of the gutsiest broads I know, physically" for doing did all her own stunts.)
- Troubled Production: Besides the Hostility on the Set between Brown, Welch, and Reynolds, director Tom Gries was hospitalised for three days during the shoot when he came down with typhus.
Trivia / 100 Rifles