Cuyamaca 100K
Descanso, United States • 3 Oct 2026
Cuyamaca 100K
The Cuyamaca 100K is an ultramarathon held in Cuyamaca Rancho State Park near Julian, CA. The course is based at Camp Cuyamaca off Highway 79 and lies mostly within the park boundaries. Runners follow three distinct loops that minimize backtracking and repeat use of the same trails.
Each loop covers a different area of the park and includes varied terrain and elevation changes. The first loop is the longest and approaches the park high point, Cuyamaca Peak, at 6500 feet. The final loop briefly leaves the park to enter Anza Borrego and follows part of the Pacific Crest Trail before returning to the park meadows and the finish area.
Distances for the three loops:
- 31.5 miles western side approaching Cuyamaca Peak
- 12.6 miles southeast corner near Oakzanita Peak
- 18.3 miles northern section with Pacific Crest Trail views
The 2026 Cuyamaca 100K is designated as a 2027 Western States qualifying race. Organizers also recruit volunteers and use a volunteer form for staffing. Visit the organization's website for the most recent information.