San Diego 100
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About the race
The San Diego 100 is an annual 100 mile endurance run held in the east county mountains of San Diego. The 26th edition uses Lake Cuyamaca near the mountain community of Julian as the start and finish venue, about 50 miles east of San Diego. The course passes through five distinct areas: Lake Cuyamaca; Rancho Cuyamaca and Anza Borrego State Parks; Noble Canyon; Mt Laguna Recreational Area; and the Pacific Crest Trail.
The route is primarily single track technical trail, covering just over 13,000 feet of climbing and a similar amount of descent. The event has a 32 hour overall time limit and intermediate aid station cutoffs. There are 16 stocked aid stations, with drop bag service at eight locations. The race is cupless and operates under a permit on the Cleveland National Forest.
Entry is limited to 300 runners on a first come, first served basis with an ordered waitlist after the field fills. Registration for the 2027 event opens January 1, 2027 at 12:01 AM. Applicants must meet qualification standards from recent long distance events to enter.
Entrants are required to perform six hours of volunteer service within the year prior to the race or donate a specified fee to support the TrailFit program in lieu of volunteer hours. Supported runners are limited to one crew vehicle; a Solo Division is available and pacers are permitted for the second half. All finishers receive a finisher buckle, an embroidered hoodie, and other mementos. Visit the organization's website for the most recent information.
