Little Missouri, a grade I winner and sire of champion and classic winner Prairie Bayou, was euthanized Sept. 8 because of the infirmities of old age. The 24-year-old pensioned son of Cox's Ridge resided at Bruce Kline's Foxhills Farm near Lexington.Bred in Kentucky by Sylvia Wood, Little Missouri raced for John Ed Anthony's Loblolly Stable. He enjoyed his best year as a 4-year-old in 1986 while trained by George R. "Rusty" Arnold, winning the Brooklyn (gr. I) and Stuyvesant (gr. II) Handicaps in New York. He also placed in four stakes that year, including the Meadowlands Cup (gr. I).Little Missouri retired with eight wins from 25 races and earnings of $553,025 in 1987. He enter stud at the Asbury family's Forest Retreat Farm near Carlisle, Ky., and while standing there sired Loblolly homebred Prairie Bayou. Second in the 1993 Kentucky Derby (gr. I), Prairie Bayou won the Preakness Stakes (gr. I) over a field that included Derby winner Sea Hero, then suffered a career-ending injury in the Belmont Stakes (gr. I) and was euthanized. A gelding, he was voted champion 3-year-old male.Little Missouri, who was out of the Jacinto mare Win Nona, later stood at Dixiana Farm near Lexington, then at Kline and partners' Spendthrift Farm near Lexington, before ending up at Foxhills. Little Missouri sired five other stakes winners, including English group winner Little Indian, and the earners of $9.6 million. He was buried in his entirety at Foxhills.