In the 1940s, Hopkins claimed he was honorary chair at a Vermont Races, though the Vermont Historical Society has no knowledge of any races in Vermont. Hopkins also claimed to have won a Texas-to-Vermont endurance race at age 21, riding an 800-pound buckskin, but there is no evidence in contemporary sources that such a race was ever held. Up to the time of his death in 1951, he remained an outspoken champion of the threatened mustang which he called "the most significant animal on the North American continent."