There was originally a fourth Barkley son, Eugene Barkley, portrayed by Charles Briles, who appeared in eight episodes of the first season. Briles was forced to leave the show midway through the first season because in real life 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.
In every episode where Nick 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), there are only two regular or recurring cast members with more than 20 appearances on the show, Lee Majors (Heath) and Linda Evans (Audra Barkley), plus Charles Briles (Eugene, only eight appearances during the first season) still living.
Richard Long, who starred as Jarrod, was the only one to ever get married, and 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 home was going to be built.
The trivia item below may give away important plot points.
Throughout the series Lee Majors in the credits was always introduced as Heath, 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.