Diablo Trail Run Marathon
Diablo Trail Run Marathon tackles steep East Bay terrain near Mount Diablo, offering technical California climbing at the full distance without requiring a 50K.
Every link above goes to the race, its timing provider, or an official registration partner. Last checked August 4, 2026.
Quick facts
- Steep Mount Diablo-area terrain
- Technical East Bay trail marathon
- Separate marathon and 50K choices
- Exposed climbing and descending
About the Diablo Trail Run Marathon
The marathon is a separate choice within the broad Diablo Trail Run weekend in Clayton. It gives mountain runners a full-distance target alongside the event's ultra and shorter trail races.
Course
The route uses steep, exposed trail in the Mount Diablo area. Sustained climbs, loose footing and fast descents demand mountain-race pacing even for athletes accustomed to road marathons.
Race-day weather
Early September in the East Bay can be very hot and dry, with little shade on open slopes. Wind and extreme fire-weather restrictions may also affect the event environment.
Past Diablo Trail Run Marathon dates and results
| Year | Date | Status | Results |
|---|---|---|---|
| 2026 | Sunday, September 6, 2026 | Upcoming | — |
Diablo Trail Run Marathon FAQ
When is the Diablo Trail Run Marathon?
The 2026 Diablo Trail Run Marathon is on Sunday, September 6, 2026.
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