Other mistake: There's a horse that has apparently ridden up a cliff, and an electrical burning brand that can be changed onto different flame settings.
Continuity mistake: Near the end, Sam Clayton is nearing the finish. The audio leads you to believe that the horse is breathing VERY hard, but when the camera shows the horse, the nostrils are NOT flared as they would be on a horse that has been run to exhaustion (or even down the block). Also, the people filming this scene obviously have no clue about the nature of sweating in horses. They showed "lather" all through the horse's mane. The ONLY places horses will lather while sweating is where something is rubbing, i.e. underneath the saddle, the bridle or breast collar, where the reins rub on the neck or between their back legs.
Other mistake: Bobby, Clovis and Celia Bradley find a large gold nugget in a mine. An assayer says gold is worth $15 an ounce and values the nugget at $87,425. That would mean it weighs 364 pounds, more than double the weight of the record-setting 173-pound gold nugget found in 1869 in Moliagul, Australia.
Continuity mistake: When John Deakin discovers the Reverend's body in the coffin, the Reverend's eyes are closed in one shot and open in the next.
Revealing mistake: When the protagonist jumps two of the evil cowboys that are after his jewels, the stuntman on the right tosses aside the rifle in a quick deliberate move pretending to lose it. (00:10:25)
Continuity mistake: When Molly dismounts her horse near the end of the movie the blanket slides off. A second later the blanket appears back on the horse.
Factual error: On their journey, Rooster is bragging about his navy colts, when actually his sidearm is a Colt .45 Peacemaker, also known as an Army Colt M1873.