The real Wyatt Earp's six-shooter was loaned by the Earp museum and used in some scenes during a number of close-ups.
Tombstone (1993) was being filmed at the same time nearby, and bought up most of the period clothing in the region. Clothing had to be imported from Europe, delaying production.
Gene Hackman receives third billing and is named on all posters, although he has less than ten minutes of screen time.
Wyatt Earp is often erroneously regarded as the central figure in the shootout near OK Corral, but his brother Virgil was Tombstone city marshal and deputy US marshal that day, and he had far more experience as a sheriff, constable, marshal, and soldier in combat. Wyatt being the more famous brother originates largely from his own self-promotion.