- Creator Backlash: When asked to comment on the film during production, actress Katharine Ross replied, "It's the biggest piece of crap I've ever done!" Then the reporter asked Vera Miles to respond to Ross' comment. She thought for a moment and said, "Well, it's not the biggest piece of crap I'VE ever done!"
- Hey, It's That Place!: When Tish Buckman and Greg Parker look at the house they plan to move into after they wed, it's the same house used as the Douglas home in My Three Sons. It was later used as one of the houses on Wysteria Lane.
- Hostility on the Set: Katharine Ross and John Wayne had many arguments over his very vocal support for The Vietnam War.
- Written-In Infirmity: Jay C. Flippen had a leg amputated due to infection in 1965 while filming Cat Ballou. That is why he played Jack Lomax as being wheelchair bound, with the reason given that the character had broken his back fighting a fire.
Trivia / Hellfighters