This pilot launches the saga of the Cannon family as they fight to establish a ranch in the Arizona territory of the 1870s. Marauding Apaches led by Cochise are on the warpath. The Army orders the Cannon family to move on, but Big John Cannon won't budge. While his brother Buck rides off to recruit gun-carrying cowhands, Big John learns of another enemy: a Mexican land baron claims the Cannon property, and dispatches his men to seize the cattle.

John Cannon's first wife is killed during an Apache raid. Buck, his brother, can't stop Mexican bandits from rustling cattle. Unable to fight on two fronts -- against Mexican marauders and the Indians -- John arranges a defense agreement with his neighbor in Mexico, Don Sebastian Montoya. The Mexican insists that John seal the agreement by marrying Victoria, his daughter, thus solidifying an alliance against the Apache. Moreover, Don Sebastian demands that Victoria's carefree brother, Manolito, come along to guarantee her safety.

Victoria's efforts to overcome husband John Cannon's memory of his first wife are thwarted when Apaches lay siege to their ranch, and she is kidnapped. Victoria is exchanged for an injured Apache and receives two opportunities to live in safety and leave the husband who doesn't love her. Former suitor Anthony Grey rides in with an offer to take her to England, as Indians attack in earnest. Don Sebastian, her father, arrives with armed vaqueros to break the siege and insists his daughter return to the safety of her home in Mexico.

John Cannon must decide whether to send his son to possible death to save their besieged ranch. Three army deserters, who have murdered Apaches on Cannon land, are taken prisoner by Indians. Captain Dabney fails in an effort to rescue the men, but gains Apache hostages, including a female relative of Cochise. When Captain Dabney refuses to trade prisoners, and as the Apaches prepare to execute the deserters (as well as Sam, who is also an Apache hostage), Cannon must decide whether to hand son, Billy Blue, the perilous job of secretly returning Dabney's hostages to Cochise. Guest Stars: Warren Stevens as Captain Dabney, Nino Cochise, grandson of Cochise as Cochise.

Buck, Manolito and Billy Blue are sent to Tucson for food, supplies and boots, but are sidetracked instead by women and song. While John Cannon awaits his trio's return with the goods, Buck promptly enters a poker game with cowhand Kansas and loses the supply money, Manolito courts Pearlita who rolls him for his money, and Billy Blue sets out with little Rag-Tag Tina to buy the fanciest pair of boots in Tucson. Problems grow when the boys try to help Fergus MacLeish and his wife from being held up, only to lose the guns they need in Tucson.

The future of the ranch is jeopardized when bandits steal a prize bull and breeding stock which Billy Blue Cannon and Manolito Montoya have bought in Mexico with the last of the Cannon money. Victoria persuades husband John Cannon to send the boys to her father's rancho for the cattle after his brother Buck Cannon is injured. Manolito bargains with his father, Don Sebastian Montoya, for his second best bull. Don Sebastian thinks the boys are pulling a prank and hires bandits to steal the bull. They boys make a desperate attempt to catch the thieves and still prove their trustworthiness.

John Cannon needs cattle from Mexican ranchers for his Army beef contract, but finds the frightened men are being forced to sell at cheap prices to a ruthless cattle buyer. When John offers them higher prices, the ranchers refuse to sell because Dolf Tanner has threatened to kill them if they do. John and brother Buck try to force the ranchers to sell by refusing them watering rights, as they drive their herds toward Tanner. But Tanner strikes back by giving Apaches new rifles and urging them to kill the Cannon herds.

Buck, Victoria and Manolito return to the Montoya Ranch and become prisoners, with Don Sebastian, of a degraded former Civil War friend of Buck. Lanier and his disheveled army announce plans to create their own state.

When Billy Blue Cannon is forced into a showdown with wanted gunfighters, he is saved by a wandering dentist who proves to be fast with a gun. John Cannon returns the favor to Doc Henry by agreeing to send Billy Blue to help the dentist establish a practice in Tucson. Billy Blue is kidnapped en route and held for ransom by the gunfighters, Jacques Dubois and Kid Curry. The boy loses faith in his new friend when the dentist throws in with the crooks. John Cannon corners Doc Henry with the ransom and prepares for a shoot-out.

Mistakes of an inexperienced eastern bank clerk who attempts to settle on a ramshackle ranch near the Cannon family threaten to wipe out the cattle industry of the territory. When Creed and Meg Hallock make repeated mistakes, John Cannon sends Buck, Billy Blue and Manolito to help them survive. Creed buys a non-existent herd and is swindled again when he innocently purchases diseased Mexican cattle. John ruins the greenhorn financially when he orders the cattle killed before they can infect other animals.

Billy Blue Cannon faces possible hanging when he is court-martialed on the charge of killing an army general's son. Billy Blue saves an Indian girl from advances by a drunken army lieutenant, who is killed in the fight. When the girl flees to the Apache stronghold, Buck and Manolito risk their lives to persuade Cochise to release Blue's only eyewitness. Her testimony is discarded when the court learns her release was obtained by a bribe. It becomes obvious to John Cannon that the court-appointed defense is incapable of saving Billy Blue, and John personally takes over his son's defense

Buck Cannon goes to work as foreman for a lovely neighboring widow, and clashes with his brother John when the job appears permanent. Buck falls in love with the widow, Melanie Cawthorne, and becomes her tool as she strives for quick riches and respectability. As water grows scarce, she buys stolen Mexican cattle from Romero without Buck's knowledge.

Billy Blue Cannon faces possible hanging when he is court-martialed on the charge of killing an army general's son. Billy Blue saves an Indian girl from advances by a drunken army lieutenant, who is killed in the fight. When the girl flees to the Apache stronghold, Buck and Manolito risk their lives to persuade Cochise to release Blue's only eyewitness. Her testimony is discarded when the court learns her release was obtained by a bribe. It becomes obvious to John Cannon that the court-appointed defense is incapable of saving Billy Blue, and John personally takes over his son's defense.

John Cannon risks breaking a mutual defense agreement with Victoria's father and dissolution of his marriage when his ranch hands join a posse searching for marauding bandits in Mexico. Marshal Virgil Shanks leads the posse into Mexico and comes into strong conflict with Buck and the Cannon cowhands when he disregards the delicacy of the situation and rides boldly onto Montoya land. Manolito finds the bandit leader, El Lobo, on his father's land and attempts to move the bandits out before the posse moves in for the kill.

Henry Silva guest-stars as a revolutionary who plans to assassinate Benito Juarez, exiled President of Mexico, on the Cannon Ranch. Manolito frees his old friend Santos from a Mexican jail, where he has been imprisoned by the French as a terrorist for Juarez. Santos and his sister, Pilar, are taken to the Cannon Ranch where Victoria arranges for Juarez to plan an invasion of Mexico. Manolito learns Santos has turned traitor and plans to conquer French-ruled Mexico himself. Before Manolito can warn his friends, Santos's followers take over the ranch and prepare to kill Juarez upon his arrival.

Fernando Lamas guest-stars as a Mexican bandit turned revolutionary who captures and prepares to execute the Cannon Ranch hands to prove his power. Manolito is jailed by El Caudillo, the Mexican bandit, when Conchita lures the group across the border. Billy Blue Cannon is allowed to escape, and he returns with El Caudillo's old enemy, Don Sebastian, and the entire group, except ranch hand Pedro, then is jailed. Hope for escape fades when El Caudillo prepares to shoot the group before frightened villagers to prove his power and to force them to join his revolution to conquer Mexico.

An Apache renegade and his followers plan to kill Cochise's peace representative in the Cannon ranch house and start a new Indian war. Medicine man Nock-Ay-Del explains that Cochise will agree to live peacefully if John Cannon offers sufficient gifts. Buck warns against a death trap when an outpost guard is killed during negotiations. Sub-chief Soldado and three warriors move in towards the ranch house to accomplish their purpose.

John Cannon and Billy Blue are captured by Apaches far from home and made to face death from lack of water. John and Billy force a wounded Indian, Klosen, to lead them toward water but the Apache escapes. Buck and Manolito catch a glimpse of a war party wearing John's and Billy's hats but harsh desert winds make it impossible to track the missing pair. When John and Billy do find water, renegade Chief Soldado ties them to a rock to die of thirst.

John Cannon drives gold seekers from an abandoned mine on his land and they retaliate by plotting to kill the Cannons. Lije Driskill, Johnny Faro and Shorty Bleeson fail in an attempt to kill Buck, Sam and Victoria, who are driving back to the ranch with dynamite to use at the mine. Driskill and his companions then raid the ranch and drive off the cattle. Buck, mistaking a friendly kiss from Victoria, leaves to dynamite the mine, and plans to make it his final job for John. Billy Blue rides to help Buck. but is captured by Driskill, who plans to kill the young m

The Cannons care for a wounded relative who repays them by stealing the ranch payroll. Uncle Dan Brookes arrives suddenly after a 15-year absence seeking safety in the heavily fortified ranch. He conceals the fact he is wanted dead or alive for murder and has been shot by bounty hunters Mace and Gurney. When Buck hires the bounty hunters as ranch hands, Brookes saves his own skin by offering to help Mace and Gurney steal the Cannon payroll.

Billy Blue Cannon plans to earn money for an expensive silver saddle by boxing. Billy Blue learns Killian and his ranch hands have entered every event in the Fourth of July rodeo to win the saddle, so the High Chaparral wranglers compete trying to help Blue, but they fail. Desperate for funds, Blue works out for five dollars with champion Paddy O'Bannion's opponent, but breaks the man's jaw. Buck convinces Blue he must fight the champ if he hopes to buy the saddle. Blue learns O'Bannion needs the fight money to marry and is torn between mixed reactions.

Buck and Manolito invade the Apache stronghold to rescuer a captive white girl. Ann, an Apache slave for five years, is rescued by Buck and Manolito as she flees from her captors, but her frail sister Olive is recaptured. John asks a passing Army detachment for aid, but the unit is massacred before it can help. Buck and Manolito ride unarmed into the Apache stronghold prepared to buy the girl's freedom, but the Apache chief and the medicine man offer to let them go free with the girl if Manolito can survive a test of courage.

Buck Cannon jeopardizes his life, when he tries to turn two Apaches into wranglers. Sourdough and Saddleblanket quickly become valuable hands. When an Apache war party kills three ranchers and kidnaps the two Indian wranglers, all but Buck believes the two Apaches are killers and have reverted to their old ways. The High Chaparral group tracks the war party to an Army fort the Indians have captured and where Buck lies seriously wounded beyond reach of his comrades. Almost dying of thirst, Buck's only chance for survival lies in an appeal to his Indian wranglers inside the fort to turn on their fellow Apaches.

Ricardo Montalban guest-stars as a wounded bandit leader who is captured by the Cannons and tells them his followers will destroy them unless he is released. When El Tigre's brother, Rafael, threatens to attack the ranch to free the notorious bandit, John Cannon has difficulty persuading his wranglers to hold the outlaw for trial in Tucson. During the attack Victoria frees El Tigre when he promises to leave peacefully and to stop the bloodshed, but he shows his true colors by making John his captive.

Billy Blue Cannon quits the ranch after a quarrel with his father and leads a peace representative of the President to Cochise. On the trail Blue falls in love with Kelly's adopted Apache daughter, Moonfire. Kelly, an idealistic dreamer, meets Cochise's demands for a strip of land separating the High Chaparral from Tucson. This would cut the Cannons' supply route and threaten them with bankruptcy. John, angered by the peace terms and his son's choice of a wife, prepares to defend the ranch against the Apaches.