However, in an episode of "Explain This" for Esquire, Russell talked about the mustache and how he almost grew it even longer to match photographs of the real-life Wyatt Earp.
Russell shared, "There was a picture that I had of him where I had the exact same mustache, but [Cosmatos], he was being incredibly accurate to certain things."
According to Cosmatos, Russell's photo was from earlier in Earp's life and didn't match how it was in 1879 when the film began, a few years before the Gunfight at the O.K. Corral.