San Diego 100
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San Diego 100 Mile Running Race
The San Diego 100 is a 100-mile endurance trail race held in the Mount Laguna Recreational Area. The course uses sections of the Pacific Crest Trail, Noble Canyon, and Lake Cuyamaca trails and operates under a permit on the Cleveland National Forest. The 2027 edition is scheduled for April 30, 2027.
Entry and event policies are specified in advance. Registration for 2027 opens January 1, 2027 and remains open until the field reaches 300 entrants or until April 1, 2027. Applicants must have completed an official 50-mile race in 13 hours or less, or a 100k or 100-mile race between January 1, 2025 and April 1, 2027. A 50% refund cutoff is set for March 15. All entrants are required to perform six hours of volunteer work within the year prior to the race and prior to April 24, 2027, or alternatively donate $105 to support the TrailFit program in lieu of volunteer hours.
The race is cupless, and aid station timing means runners who start earlier than the main field should be prepared to self-support until the Cuyamaca Peak aid station. Completing the San Diego 100 within 32 hours qualifies a runner to enter the Western States 100 lottery. The event includes two Scotty Mills Scholarships offering up to two free entries; applicants prepare a short write-up and submit it by December 28 for consideration. Visit the organization's website for the most recent information.
