Diablo Trail Run
Diablo Trail Run offers challenging mountain courses with spectacular Bay Area views.
Race Date
Sep 6, 2026
Location
Clayton, CA
Quick facts
- Date
- Sunday, September 6, 2026
- Location
- Clayton, California
- Distance
- Half marathon (13.1 mi) + 4 Miles, 10 Miles, 26.2 Miles, 30.4 Miles
- Course
- Loop Course
- Terrain
- Trail
- USATF certified
- Not listed
- Finishers on record
- 245
Highlights
Good For
Atmosphere
Course
The Experience
The Diablo Trail Run series, held annually through 2025, challenges runners with mountainous terrain set against the spectacular backdrop of the San Francisco Bay Area. While the shorter 4-mile event navigates the relatively flat and fast Mitchell Canyon, the longer distances, including the half-marathon, are decidedly mountainous and scenic.
This event, first run in 2023 and now in its third edition, typically sees around 76 finishers. Runners come from approximately 3 states, with a repeat-runner loyalty rate of about 16%. The challenging courses are accurately measured, ensuring a true test for participants.
Runners can expect typical race-day temperatures ranging from 62–90°F, making for a potentially warm but scenic race day. The series offers a variety of distances, from 4 miles to ultra-marathon lengths, catering to a range of trail running enthusiasts.
Race-provided description
Mount Diablo provides spectacular views of the San Francisco Bay Area and surrounding valleys. The 4 mile course is relatively flat and fast within Mitchell Canyon. The longer events are mountainous and very scenic. (Distances are accurately measured using a Rolatape® surveyor's measuring wheel.)
Logistics
Race Day
Sunday, September 6, 2026
Start Time
8:00 AM
Giveaway
T-Shirt
Start Location
Diablo State Park (Mitchell Canyon Trailhead), Clayton, CA, 94517
Course Info
Course Type
Loop Course
Terrain
trail
Scenery
Mountain, Urban
Surface
Dirt Trail
Difficulty
Mountainous
Net Drop/km
0 m (Flat)
Separation
0.0%
Also Offers
Quality Score
Solid Pick443 years running
~76 finishers a year
growing or steady
16% returning runners
3 timing sources
runners from 3 states
winner 1:52:02
typical high 90°F
Race Day Weather
5-year historical avgStart (Low)
62°
Afternoon (High)
90°
Hot conditions — adjust pace expectations, prioritize hydration
0.0"
Precipitation
11 mph
Wind
48%
Humidity
Historical Finish Times
How 245 finishers actually crossed the line across 3 years.
Most recent
2025
Total finishers
245
Median time
3:12:27
Latest turnout
76
States
10
Turnout by year
2023–2025
Hover the histogram to inspect specific finish times.
Race Photos
Frequently asked
When is the Diablo Trail Run?
The Diablo Trail Run is held on Sunday, September 6, 2026, starting at 8:00 AM.
Where does the Diablo Trail Run take place?
It takes place in Clayton, California.
What distances does the Diablo Trail Run offer?
The half marathon (13.1 miles), plus 4 Miles, 10 Miles, 26.2 Miles, 30.4 Miles.
Is the Diablo Trail Run course flat and good for a PR?
The Diablo Trail Run is a mountainous, loop course course.
How many people run the Diablo Trail Run?
HalfRuns has finish records for 245 runners who have completed the Diablo Trail Run.
HalfRuns editorial — independent, no paid placement.
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