Diablo Trails Challenge
Walnut Creek, United States • 4 Apr 2026
Diablo Trails Challenge
The Diablo Trails Challenge is a trail running event on Mount Diablo organized by Brazen Racing. The event takes place on April 4, 2026.
Participants can choose from four distances:
- 50K
- Half Marathon
- 10K
- 5K
The event was created to help celebrate and support the work of Save Mount Diablo, a conservation organization. A portion of all entry fees goes to the organization to support its work preserving open space and trails. The half marathon distance is part of the Brazen Ultra Half Series, which consists of half marathons noted for significant ascents, descents, and tough trails. Visit the organization's website for the most recent information.