Factual error: Graham repeatedly sings a song he says his grandmother taught him: "Rufus Rastus Johnson Brown, What You Gonna Do When the Rent Come Round?" This was a Vaudeville stage composition written by Andrew B. Sterling and Harry Von Tilzer - in 1905. High Chaparral is set in the 1870s.
Continuity mistake: Blue is struck by a rifle stock and has a bleeding wound on his left temple. A few shots later, though, the wound disappears completely. Several scenes later, it's back again.