Continuity mistake: In the final fight scene between John Wayne and the bad guy, Wayne gets struck in the head, and as he falls backwards over the wagon tongue his toupee lifts off.
Continuity mistake: McQueen and Brynner take a hearse up the hill to deliver a coffin to the graveyard. When they go back down the hill, you can see a plume fall off one of the horses' heads, but in the next shot, the plume is back on. (00:16:05)
Continuity mistake: In an early scene Travis and Dickenson are in Travis's office. Travis goes to the mantel, gets a cigar and pours himself a glass of sherry. In a later scene, when Travis meets Crockett in the cantina he refuses a drink from Crockett claiming he doesn't drink, ever.