There was originally a fourth Barkley son, Eugene (Charles Briles), who appeared in eight episodes of the first season. Briles was forced to leave the show midway through the first season because he was drafted by the U.S. Army. After leaving the regular cast, Eugene never returned in later seasons, even when Briles mustered out of the Army, and basically, Eugene was never really referred to again.
Victoria (Barbara Stanwyck) is the only Barkley who was never shot throughout the run of the series. Heath (Lee Majors) was shot the most, and Nick (Peter Breck) has the distinction of being the only Barkley who is shot twice in the same episode.
In every episode where Nick (Peter Breck) is a spectator in a court case, he interrupts the court to speak his peace, which always gets him into trouble with the judge who is presiding. In later episodes throughout the series, this took on a comedic tone, as the viewer knew that it was only a matter of time before Nick would voice his displeasure.
The series was loosely based on the Hill Ranch, which was located on the western edge of Calaveras County in California. Lawson Hill started the ranch and ran it until his death in 1861. He and his wife Euphemia had four children, three sons and one daughter.
With the February 6, 2012, death of Peter Breck (Nick) and the June 12, 2016 death of Charles Briles (Eugene; only eight appearances during the first season), there are only two regular or recurring cast members with more than twenty appearances on the show, Lee Majors (Heath) and Linda Evans (Audra).
Jarrod (Richard Long) was the only one to ever get married. It only lasted a few days after only meeting a week before. She died accidentally taking a bullet for Jarrod when leaning over to pick a flower while picnicking beside a stream where their future house was going to be built.
The entire family, minus Eugene (Charles Briles), have all killed throughout the show. Audra (Linda Evans) killed two men during the first season; Nick (Peter Breck), Heath (Lee Majors), and Jarrod (Richard Long) killed many people throughout the series, and Victoria (Barbara Stanwyck) killed at least two people in each season.
In episode 30 of Season 2, "Cage of Eagles" Nick mentions to Madigan that the eagle he captured was going after their chickens and sheep but the introduction of sheep to the Barkley ranch didn't happen until episode 3 of Season 3, "Flock of Trouble"
Throughout the series, Lee Majors was always introduced as Heath in the credits, no last name. This was because, even though he was accepted as a member of the family, there was always the question of whether he was a true Barkley or not.