San Diego 100
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San Diego 100 Mile Endurance Run
The San Diego 100 Mile Endurance Run is an annual 100 mile trail race held in the east county mountains of San Diego. The 26th edition is scheduled for April 30 to May 1, 2027. The start and finish venue is at Lake Cuyamaca near the mountain community of Julian, 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, the Mt Laguna Recreational Area, and the Pacific Crest Trail. About 85% of the route is single-track technical trail, and the course includes just over 13,000 feet of climbing and a similar amount of descent. The race has a 32 hour time limit with intermediate aid station cutoffs. There are 16 aid stations and drop bags are available at 8 of those stations. The event is cupless and operates under a permit on the Cleveland National Forest.
Registration opens on January 1, 2027 and remains open until the field reaches 300 entrants or until April 1, 2027, on a first-come, first-served basis. Applicants must meet race qualification criteria from the 2025–2027 period. Entrants are required to perform six hours of volunteer work in the year prior to the race or donate an alternative fee to support local trail work. Supported runners are limited to one crew vehicle; a Solo Division and pacer rules are provided for runners and crews. Finishers receive a buckle and an embroidered hoodie and podium awards are given. Visit the organization's website for the most recent information.
