Factual error: On the second day of the trio's journey from setting out from Ft. Smith Arkansas the scenery jumps to the landscape of the Black Mesa near Santa Fe New Mexico. The credits substantiate that indeed some scenes were shot in this area. Ft. Smith is 729 miles from Santa Fe. The terrain near Ft Smith is mostly wooded for hundreds of miles.
Factual error: Campbell is armed with what is described by Wayne as a "buffalo gun", a large bore rifle known for its power and substantial recoil. Campbell shoots a wild turkey with the gun and causes the meat to be severely damaged. Wayne comments, "Too much gun" emphasizing the power of the gun. However, when Campbell shoots the turkey with this "buffalo gun" there is no visible recoil.