The notorious Shelton brothers (Robert J. Wilke, Warren Oates) ride into North Fork to take revenge on Micah Torrance (Paul Fix), an ex-lawman who is now crippled with alcoholism.
Lucas tries to help a young West Point reject (Robert Vaughn), who is filling in as marshal, just as the town erupts into a gunfight.
Lucas and Mark return from a cattle sale when their stagecoach is robbed by three outlaws led by sharpshooter Johnny Cotton (Vic Morrow).
Wanting to teach Mark about tolerance and acceptance, Lucas hires an injured and bitter confederate soldier (Royal Dano) to work on his ranch, only the Union army also arrives at the farm.
When Abel Goss (John Carradine), a photographer friend of the McCains, is accused of murder, father and son take opposing views on the matter.
Marshal Sam Buckhart (Michael Ansara) arrives in North Fork to look for Indians who are suspected in the brutal murder of a Ranger and his family.
Guest stars: Herbert Rudley, Mickey Simpson, Frank DeKova, Eddie Little Sky, Bill Quinn Julia Massini (Katy Jurado), a reformed gambler, runs a respectable boarding house in North Fork, but her old boss (Alan Baxter) shows up and tries to force her to turn her place into a gambling house.
Released from Yuma prison, Dan Maury (Lee Van Cleef) arrives in North Fork intent on getting even with Marshal Torrance, who helped send him to jail.
A neighboring rancher (George Mathews) refuses medical assistance when his son is seriously hurt in an accident because he blames doctors for the death of his wife.
Bookkeeper Asa Manning (William Phipps) hires a professional gunman (John Dehner) to provoke Oat Jackford (Bert Freed), a bully rancher who suspects him of embezzlement, into a gunfight.
Accused of a murder he did not commit, a young man (Michael Landon) is finally cleared by the accidental discovery of a "mind reader" (John Carradine).
After a wanna-be bounty hunter (Harry Dean Stanton) kills a man (Gregory Walcott) wanted for a crime committed long ago, Lucas and Mark try to protect the widow (Sydna Scott) from learning about her husband's criminal past.
Eddie's daughter (Gloria DeHaven), who is withholding criminal information and stolen money, comes to meet her father (John Harmon) and causes trouble for Lucas.
Lucas discovers a young married couple (William Joyce and Enid Janes) with yellow fever and cares for them at his house, but Mark lets out the secret which causes panic in town.
Lucas makes a life-and-death decision when Micah is held hostage and the kidnappers demand the release of a notorious outlaw (Vic Morrow).
A singer (Phyllis Avery) asks Lucas to care for her daughter in an effort to hide the child from its bigoted father (John Dehner).
Lucas becomes involved in a battle between a recently fired cook (Carleton Carpenter) and a cocky trail hand (Steve Rowland) who finds it fun to attack those weaker than himself.
The body of a notorious outlaw, the Domino Kid, is brought in by Colly Vane (Robert Culp), who doesn't get the reward for he shot the man in the back.
The Averys (Chubby Johnson, Ellen Corby), Lucas' new elderly neighbors, live under an assumed name to keep the town from knowing they are the parents of a vicious wanted killer (Skip Homeier).
An aging Southern belle and her teenage son arrive in North Fork and immediately identify Micah as her long-lost husband and father of the boy.
Lucas develops temporary amnesia from a head injury while visiting a strange town and mistakenly assumes the identity of a wanted criminal.
Lucas, Lou Mallory, Doctor Burrage and two innocent bystanders are trapped in the hotel with dangerous outlaw Lee Coyle (Ed Ames) after a smallpox epidemic.
Wade Randall (Sammy Davis, Jr.) appears in town, bragging of his gun battles with notorious bad men, until one of them (Richard Devon) shows up to challenge him.
Mark develops an intense aversion of his father's rifle after a shooting accident takes the life of his friend (Jimmy Carter).
Outlaws, who had elected not to rob North Branch due to its heavily-armed reputation, change their minds upon learning of a new policy disarming the citizenry.
Lucas and Mark find Winslow Quince (Kevin McCarthy) stranded in the desert with a broken wheel on his wagon and help him to get to town.
Grid Maul, a boy not much older than Mark, confronts Lucas with the announcement that he intends to kill him to avenge his father's death.
North Fork welcomes the arrival of the first train on the new railroad and with it, visitors that include a royal cousin of the Emperor of Japan (John Fujioka).
Away on a trip for the Cattleman's Association, Lucas rescues a man and is drawn into a fight with the crooked owner of a gambling establishment (Richard Anderson).
The recluse Old Tony (Stefan Schnabel) helps Lucas rescue Mark and his girlfriend Lorrie (Karen Sue Trent) from quicksand.