Continuity mistake: At the end of the film when all the women are dressed up after making clothes out of tablecloths, you can see the Italian woman riding in the front of the wagon. The shot changes and she's riding on the side looking at all the men and smiling. The shot changes again and she's back to the front.
Revealing mistake: When Captain Quincy Wyatt interrogates a captive Seminole Native American by threatening him with a poisonous snake, the native is safe because there is a protective piece of glass between him and the snake. The snake's reflection is quite obvious on the glass panel. (01:14:40)
Revealing mistake: When The Indians launch their final attack (towards the end of the film), on a old outpost held by a small group of soldiers, Ward Bond is hit by a arrow which enters the right side of his chest. In the next shot you see Gregory Peck removing the arrow from the left side of Ward Bond's chest.
Continuity mistake: When we see Nasty Canasta's drink, you can see there are holes on the counter next to the glass when the bartender puts two ice cubes in it. When Daffy Duck dares Nasty Canasta to drink it, the holes have disappeared.
Other mistake: A brief section of the film was flipped. One building has a sign saying "FIREARMS" and the lettering is in reverse.