Corrected entry: Dragon's dog, a Rottweiler, was not in the US until 1931, much later than the show.
Continuity mistake: Marshall Dillon buries an outlaw at Sarah's place. He installs a wood cross at the grave. Sarah comes out and they talk. When she leaves, the scene cuts back to Dillon and the cross is missing.
Dr. Galen 'Doc' Adams: I'll tell you why the Hagens live so long.
Festus Haggen: Why?
Dr. Galen 'Doc' Adams: 'Cause they're too dumb to know they're dead.
Trivia: Although they played father and son in this episode, Jack Elam was only six years older than Harry Dean Stanton.
Correction: The Rottweiler is considered one of the oldest breeds. It was only in 1931 that the American Kennel Club recognized the Rottweiler as an official breed. There's a difference between a breed existing and being recognized by a kennel club.
Bishop73