Diablo Trail Run
Clayton, United States • 6 Sep 2026
Event overview
The Diablo Trail Run takes place on Sunday, September 6, 2026, at Diablo State Park (Mitchell Canyon Trailhead) in Clayton, CA 94517. The event offers multiple distances:
- 4 Mi
- 10 Mi
- Half Marathon
- Marathon
- 50K
- Kid's Run (6yo & younger, 50yd dash)
- Coastal Testing
Distances are measured with a Rolatape surveyor's measuring wheel. Parking at the trailhead is $6 per vehicle. No dogs are allowed on the course. To guarantee a shirt, registration must be completed 10 business days before the event. There is no bag check, but non-valuables may be left at the start/finish.
Course and race services
The 4 mile course is relatively flat within Mitchell Canyon; longer events include mountainous terrain and scenic sections. The course is marked with ribbon about every 200 yards and uses polka-dot flagging to indicate turns. Routes are color coded by distance. Elevation gain and surface breakdown by distance:
- 4 mi: Elevation Gain 400'; dirt road 100%
- 10 mi: Elevation Gain 2,420'; dirt road 100%
- Half Marathon: Elevation Gain 3,420'; single track 21% dirt road 76% asphalt 3%
- Marathon: Elevation Gain 6,760'; single track 28% dirt road 70% asphalt 2%
- 50K: Elevation Gain 8,000'; single track 38% dirt road 60% asphalt 2%
Fully stocked aid stations appear every 3–5 miles with fruit, salty snacks, candy, water, and Skratch electrolyte drink. The event operates cupless aid stations; participants are asked to bring their own fluid container. Visit the organization's website for the most recent information.