Jack Johnson (as played by Buck Taylor in Tombstone) rode with Wyatt Earp and company on the infamous Vendetta Ride of 1882, when a number of Cow-boys were killed to avenge the death of Morgan Earp. Johnson apparently was a former Cow-boy who switched sides.
He would go down in popular history as “Turkey Creek Jack.” But researcher Peter Brand—quoting Wyatt Earp–says the man’s real name was John Blount. And he was first called “Turkey Creek Jack” in Stuart Lake’s fanciful bio of Earp—not during the man’s lifetime. Blount died in 1906.