The High Chaparral (1967) : 3x6

Left in charge of the Chaparral, Blue fails in his first major test of responsibility and then takes drastic steps to redeem himself. In the absence of his father, John Cannon, his Uncle Buck and Manolito, Blue is given full authority to run the ranch only to have their prize stallion stolen by bandits. Hurt by his father's criticism and determined to regain his confidence, Blue faces the bandits alone in his attempt to retrieve the valuable horse.