2027 Diablo Summit Stomp
Diablo Summit Stomp: a small, loyal half on Mount Diablo.
Expected Race Date
~Oct 2027
Date not yet announced — this is when the race usually runs.
Location
Walnut Creek, CA
Quick facts
- Date
- around October 2027 (expected)
- Location
- Walnut Creek, California
- Distance
- Half marathon (13.1 mi)
- Course
- Loop Course
- Terrain
- Road
- USATF certified
- Not listed
- Finishers on record
- 904
Highlights
Atmosphere
The Experience
Now in its 11th edition, the Diablo Summit Stomp draws a dedicated field of around 104 runners, with 17% returning year after year. Runners come from about 5 states to tackle the half-marathon (and accompanying 30K, 10K, and 5K) on the slopes of Mount Diablo in Walnut Creek, California. This is a low-key event that prioritizes community over crowds—perfect for those seeking a no-frills, local race with a loyal following.
The course, described as a loop on pavement, takes runners through the rolling terrain of the Diablo foothills. Though official elevation data is absent, the name suggests a challenging, scenic route. The small field means plenty of personal space, and the finish area offers a modest post-race gathering. For runners looking to combine a race with a visit to the East Bay, this under-the-radar event delivers a genuine, unfussy experience.
Race-provided description
The Diablo Summit Stomp is on Saturday October 18, 2025. It includes the following events: 30K, HALF MARATHON, 10K, 5K, Half Hiker Division, and 30K Hikers.
Logistics
Race Day
around October 2027 (expected)
Start Time
TBA
Start Location
1700 Castle Rock Rd, Walnut Creek, CA, 94598
Course Info
Course Type
Loop Course
Terrain
road
Difficulty
Rolling Hills
Quality Score
Solid Pick5712 years running
~104 finishers a year
shrinking
16% returning runners
7 timing sources
runners from 5 states
winner 1:58:06
typical high 74°F
Historical Finish Times
How 904 finishers actually crossed the line across 8 years.
Most recent
2026
Total finishers
904
Median time
3:16:54
Latest turnout
90
States
19
Turnout by year
2018–2026
Hover the histogram to inspect specific finish times.
Frequently asked
When is the 2027 Diablo Summit Stomp?
The 2027 Diablo Summit Stomp hasn't announced its next date yet, but it typically takes place around October 2027 (expected).
Where does the 2027 Diablo Summit Stomp take place?
It takes place in Walnut Creek, California.
What distances does the 2027 Diablo Summit Stomp offer?
The half marathon (13.1 miles).
Is the 2027 Diablo Summit Stomp course flat and good for a PR?
The 2027 Diablo Summit Stomp is a rolling hills, loop course course.
How many people run the 2027 Diablo Summit Stomp?
HalfRuns has finish records for 904 runners who have completed the 2027 Diablo Summit Stomp.
HalfRuns editorial — independent, no paid placement.
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