San Diego 100
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San Diego 100 - April 30, 2027
San Diego 100 is a 100 mile mountain ultramarathon held at Lake Cuyamaca Recreation Area near Julian, California. The event is a loop course made up of about 90% single track and traverses sections of the Pacific Crest Trail, Noble Canyon, Cuyamaca and Anza Borrego State Parks, and Mt Laguna recreational areas. The course has approximately 15,600 feet of climbing and an equal amount of descent, and it is run to a 32 hour time limit.
Distances
- 100 Miler Crewed
- 100 Miler Solo
The Solo division requires runners to complete the race without crew or pacers; Solo runners may only be met by spectators at the start and finish and must rely on drop bags and staffed aid stations for support. Registration opens January 1, 2027 at 12:01 AM and remains open until the event reaches 200 entrants or until April 15, 2027; a waitlist is maintained if the race fills.
Entry prerequisites include a qualifying performance such as a 50 mile finish under 13 hours between January 1, 2025 and April 1, 2027, or an equivalent 100K or 100 mile result within the same timeframe. Applicants must also complete six hours of trail maintenance or volunteer service between May 1, 2026 and April 15, 2027, or donate $100 in lieu of trailwork. A limited number of scholarship entries and discounts for active military and first responders are offered. Visit the organization's website for the most recent information.
