Mark your calendar for the Diablo Marathon on Sep 6, 2026, USA's 2026 running calendar wouldn't be complete without it, with the action centred in Clayton, California, USA. This course is perfect for fans of hills. Runners start at the Mitchell Canyon Trailhead.
🏃 Why Run This Race
- Challenging hilly terrain that rewards strong, well-trained runners
- Off-road trail experience through stunning natural surroundings
- Well-organised aid stations and on-course support throughout
- Welcoming local running community in Clayton, California
- Finisher medal, race day swag and post-race celebration for every participant
🏁 Race Distances & Events
- 50K Ultra Marathon
- Marathon (26.2 miles / 42.2 km)
- Half Marathon (13.1 miles / 21.1 km)
- 10M Race
- 4M trail run
- Kids Run
🗺️ Course Highlights
- Almost immediately they are faced with a steady incline, climbing six miles to a peak of almost 4,000 feet.
- They are then rewarded the payback of a decline, if sometimes interrupted, for the next 8 miles.
- The remaining 12 miles is a near repeat of the first 14.
📅 Event Details
- Date: Sep 6, 2026
- Location: Clayton, California, USA
- Available distances: 50K Ultra Marathon | Marathon (26.2 miles / 42.2 km) | Half Marathon (13.1 miles / 21.1 km) | 10M Race | 4M trail run | Kids Run
💡 Runner Tips
- Train with hill repeats and strength work in the weeks leading up to race day
- Wear grippy trail shoes and bring a hydration pack for longer distances
Whether you're chasing a personal best, ticking off your first marathon, or simply enjoying the running community, the Diablo Marathon delivers an unforgettable race day. Register early, entries for popular distances fill quickly. Secure your spot at one of USA's premier 2026 running events today.