Lake Sonoma 100K, 50K, TS Half Marathon
Decision scores
Six 0–100 scores telling you, at a glance, who this race is for.
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About the Race
Join us in Healdsburg, California, on April 11th 2026 for the TERREX Lake Sonoma 100K, 50K, and Trail Sisters Half Marathon! We are excited to have adidas TERREX back as our presenting partner! We are stoked to team up with Mountain Outpost to bring you full livestream coverage, athlete panels, interviews, and commentary from special guests! Lake Sonoma 100K The 100K course will start with a climb up Pritchett Peak with a water only stop at the top. Once you reach the summit you’ll head back ...
Course Profile
Course profile data unavailable for this race.
Course features
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History & past results
Past finisher times and year-over-year participation will appear here once the organizer publishes them.
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Common questions
How hard is the Lake Sonoma 100K, 50K, TS Half Marathon Half Marathon?
We don't have a verified elevation profile yet — check the organizer's course map for the climb breakdown.
What should I wear?
Dress for ~10°F warmer than the standing temperature once you start running. Throwaway long-sleeve at the start, gloves and a hat for sub-50°F mornings, singlet plus visor when it climbs above 60°F. The race-day forecast above is the source of truth closer to the date.
When does it sell out?
No published deadline. Most races raise the entry fee in tiers and can sell out without warning — sign up early if you're committed.
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