At about the 23 minute mark where the doctor is talking to the lawman, a "Wanted" poster can be seen offering a reward for a "Bronco Layne", who was the title character from the early 60's Ty Hardin western series "Bronco".
Mike Farrell plays a doctor, and in the script he explains that he had served as a doctor in the army. This was 3 years before he starred in MASH as an Army doctor.