Griswold, who won three titles as Quarter Horse distance champion in the early 1990’s, and is widely considered the finest 870-yard Quarter Horse in history, was euthanized on June 23 because of infirmities of old age, according to Shaun Hadley, ranch manager of Legacy Ranch in Clements, Calif.Griswold, a gelding, was 25 and had spent the last years of his life in retirement at Legacy Ranch, which is owned by Pete and Evelyn Parrella, who raced Griswold. An accomplished horse in Quarter Horse straightaway races, including a third in the 1989 Champion of Champions, Griswold was a trendsetter at 870 yards, setting a track record of 43.99 seconds that stands today.He may be best known for a race he lost, an epic match race against the Thoroughbred Valiant Pete at Santa Anita in April 1991. In a $100,000 race over a half-mile, Griswold and Valiant Pete dueled around the turn and through the stretch before Valiant Pete won by a neck before an ontrack crowd of more than 37,000.At his home base of Los Alamitos, Griswold won 14 stakes and earned $582,346 in his career. His major wins included the 1989 Governor’s Cup Derby over 400 yards, the 1991 and 1993 Marathon Handicap and three runnings of the Breeders’ Marathon Classic. He was the champion distance horse from 1991-93.