from the article the OP poasted
Hadji Halef Omar is a purebred Arabian endurance horse who has logged 8,575 lifetime miles over 170 American Endurance Ride Conference (AERC) rides
We rode competitive trail rides against a horse named Elmer Bandit
In September 2009 owner Mary Anna Wood and Elmer completed the Stephens Forest Competitive Trail event near Lucas, Iowa, which pushed Elmer’s lifetime mileage to 20,780 miles, surpassing the previous record held by Wing Tempo (an American Saddlebred who said they just look flashy and go in circles) ).
Elmer won numerous National Championships over his 34-year career... he was 37 when he did the Stephens Forest Competitive Trail ... he died the following winter