Factual error: After the first encounter with the Apaches, the covered wagon is headed to the Fort at full speed. The camera pans to the Apaches on the ridge and you can see a truck driving at the bottom right corner. (00:32:00)
Factual error: When the riders are watching the wagon train, in the background you can see a communication tower with conical speakers.
Continuity mistake: When Sam says to Bugs, "This town ain't big enough for the two of us", Bugs is holding a carrot in his right hand. When Bugs runs out of the saloon in the next shot, the carrot he was holding has disappeared.