John Ford had a greensman water a cactus overnight to allow it to be squeezed for water.
John Wayne's character, Robert Marmaduke Hightower, was named by director John Ford after his favorite stuntman, Bryan 'Slim' Hightower, who also worked on this picture.
For the scene where Deputy Curly (Hank Worden) has trouble pulling a mule about a train, director John Ford rigged the reins to pull backwards whenever Worden pulled forward.
This is a remake of the silent film The Three Godfathers, which starred Ford's long-time friend Harry Carey. When Carey died in 1947, Ford decided to remake the story in Technicolor and dedicate the film to his memory. Carey's son, Harry Carey Jr., plays one of the three, "The Abilene Kid".
When John Wayne is "greasing" the baby boy, Robert William Pedro, it is evident that the baby boy is actually a baby girl.