The early trail 100-mile races, including Western States 100, Old Dominion 100, and Vermont 100, all have their roots in horse endurance rides. The parallels from those rides to 100-mile ultras are many. Much of the experience and practices of those rides became part of trail 100 mile runs that were established in the 1970s and ‘80s.
In 1955 Wendell Robie, a successful businessman and outdoorsman from Auburn, California had a discussion with an associate about whether a horseback rider could cover 100 miles in a day. He got riled up about it and vowed to prove it could be done. He wanted to conduct the ride on a trail he had particular interest in, a historic trail used by miners in the 1800s between the California gold fields and the silver mines in Virginia City, Nevada. Wendell named the trail, “The Western States Trail.” It went through little old gold towns between Lake Tahoe and Auburn, Califronia, crossing over the crest of the Sierra Nevada Mountains. Wendell made plans, established a committee, and worked to get support from the city of Auburn. A stated purpose of the ride was “to determine if Western horses are bred today as tough as those of the Pony Express era.”