Continuity mistake: 4-23, "Ride a Cock Horse to Laramie Cross": The dye job on young Clint Howard's hair is inconsistent from scene to scene. It's dark black at the start, but pales to a shade much closer to his natural blond color in many shots later on. His brown make-up (a laughable effort to make a blue-eyed Anglo kid look Hispanic) also varies, and disappears entirely in some of the covered wagon scenes.
Continuity mistake: The miniature train used in all the night shots (it passes the same artificial mountainside several times), is pulling three passenger cars and no baggage car. When the full size train arrives at the station the next day, it has a baggage car and only one passenger car.