Lake Sonoma 100K, 50K & TS Half
Apr 10, 2027Healdsburg, CA100K, 50K +1
Also 100K, 86 mi from Dick Collins Firetrails
At a glance
- Last held
- Sep 26, 2026
- Next edition
- 2027 date not announced. Usually held in September.
- Location
- Castro Valley, California
- Distances
- 100K, 50 mi, Marathon
- Aid stations
- 2, 1 with crew access
Listed from UltraSignup. Checked Sep 25, 2026.
Plan this race for free
2 aid stations are already loaded. Add cutoffs, pacing and the timeline your crew follows. Crew invites and race-day updates come with a Race Pass.
Build my planAbout this race
The 43rd Annual Dick Collins Firetrails is a historic ultrarunning event held at Lake Chabot Marina in Castro Valley, CA, featuring a 100k, 50-Mile, and Marathon on trails in the East Bay Regional Parks.
Key dates
Early ends
Apr 10, 2026
Registration closes
Sep 25, 2026
Race day
Sep 26, 2026
Pricing
Bay Ridge 100k
After Apr 11
$245
Firetrails 50 Miler
After Apr 11
$220
Golden Hills Marathon
After Apr 11
$125
Email me updates about Dick Collins Firetrails
Registration openings and major changes, like a new date or a cancellation.
Aid stations
2| Station | Distance | Crew | Drop bags | Cutoff | Supplies |
|---|---|---|---|---|---|
Big Bear Drop bags are supported at Big Bear. Bags transported from start on race morning. Drop bags not returned to Start/Finish until after 7pm when Big Bear closes. Pacers can enter at Big Bear (returning only) for 100k and 50-mile. | -- | -- | Skratch sports drinkGu gels | ||
Rancho Laguna Out-and-back destination for the 100k course. Pacers can enter the course here for 100k and 50-mile. | -- | -- | Skratch sports drinkGu gels |
Entry transfers
Can't race, or need an entry? Post it here so nobody has to ask if it's still available.
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Race planning
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