San Diego 100
Julian, United States • 8-9 May 2026
The San Diego 100 is a challenging 100-mile ultramarathon held in the mountainous east county of San Diego, California, starting and finishing at Lake Cuyamaca Recreation Area. The course is a 90% single-track loop featuring rugged terrain with approximately 15,400 feet of elevation gain and loss. It traverses scenic areas including the Pacific Crest Trail, Noble Canyon, Cuyamaca and Anza Borrego State Parks, and Mt Laguna. Known for its hot, dry conditions and technical difficulty, the race offers strong volunteer support and a 32-hour cutoff. It serves as a Western States 100 qualifier and includes a Solo Division for unsupported runners. Visit the organization's website for the most recent information.