Originally Aired: June 1, 1958

In Gunsmoke #321, "Quarter Horse," an elderly rancher named Mr. Thatcher faces relentless ridicule from Ed Butler and his cronies at the Long Branch Saloon over his peculiar-looking quarter horse colt. After Marshal Matt Dillon intervenes to stop Butler's bullying, Thatcher approaches the marshal with a bold proposition: he wants to challenge Butler to a grudge race, wagering his entire ranch against Butler's claim of having the finest horses around Dodge. Despite the marshal's reluctance to get involved in personal disputes, he agrees to hold the stakes and ensure a fair competition. Thatcher passionately defends his unconventional colt, describing its low-slung build and powerful muscles, insisting it's the fastest horse west of St. Louis.

As race day arrives and half the town gathers at the river flats to watch, tensions escalate. Butler surprises everyone by entering a thoroughbred instead of a cow pony, and Thatcher begins drinking heavily. When Butler coldly reminds Thatcher that the wager includes not just the ranch but the prized colt itself, the old man realizes the devastating stakes of what he's risked. With Doc Adams and Mr. Hightower serving as judges and Chester preparing to fire the starting gun, the race is set to begin with everything Thatcher owns hanging in the balance.