Diablo Trails Challenge
Walnut Creek, United States • 4 Apr 2026
Diablo Trails Challenge is a trail-running event held at 1700 Castle Rock Road, Walnut Creek, CA, in support of Save Mount Diablo. The race offers multiple distances to suit all levels: 50K, half marathon, 10K, and 5K, plus a Remote Runner option. The course traverses Mount Diablo’s open-space trails, appealing to both first-time trail runners and seasoned ultramarathoners. A portion of each entry fee benefits Save Mount Diablo to help preserve and expand the region’s open space and trails. The event celebrates trail achievements and community involvement, with extras such as a BBQ lunch option for participants. Visit the organization's website for the most recent information.