In 175 days · Sat, Apr 3, 2027
Don't let race day sneak up
One email during race week. That's it.
Saturday, April 3rd, 2027
1700 Castle Rock Rd, Walnut Creek CA
Half · 5K · 10K
47–67°F · low rain risk
See last 10 years
On this date: rain 0 of the last 10 years
2026
50–71°F
dry
2025
43–62°F
dry
2024
47–61°F
dry
2023
38–55°F
dry
2022
48–75°F
dry
2021
46–61°F
dry
2020
41–63°F
dry
2019
51–62°F
dry
2018
46–74°F
dry
2017
46–72°F
dry
Best months to race in California →
Going long?
Fuel wins races.
Gels, chews, electrolytes, anti-chafe — everything for 13.1 and beyond.
About this race
Event Overview
The Diablo Trails Challenge 2027 will take place on April 3, 2027, at 1700 Castle Rock Rd, Walnut Creek, CA. For more information, visit the official race page.
About Save Mount Diablo
- Mission: For over 40+ years, Save Mount Diablo has worked tirelessly to preserve and increase the open space on and around Mount Diablo.
- Acres Preserved: Their efforts have taken us from 6,788 acres of open space to over 100,000 acres of open space on and around the mountain!
- Contribution: A portion of all entry fees will go to Save Mount Diablo to help them continue preserving open space and trails for all of us to enjoy.
Race Details
- Distances: The event features distances suitable for everyone from those hitting the trails for the first time to experienced ultra-runners.
- Purpose: The Diablo Trails Challenge was created to help celebrate and support the achievements of Save Mount Diablo.
Course map
Train with a club
Run clubs near Walnut Creek to train with before race day.
Suggested Races
Organize this race?
Claim it free to manage your listing — and get it featured for free, while spots last.