Lake Sonoma 100K
2027 at a glance
- EntryNot confirmed yet
- Race day
- ResultsAfter race day
- Race day
- Apr 10, 2027 Saturday
- Distance
- 100 km Ultramarathon
- Entry
- Not confirmed
- Latest results
- 2026
Quick facts
- Sunrise climb to Pritchett Peak
- Follows the original Lake Sonoma 50 Mile out and back
- Western States qualifier for sub-19-hour finishers
- Bottle of wine for every finisher
Course
The 100K starts at the Lake Sonoma Visitor Center with a climb to Pritchett Peak, returns past the visitor center and heads up to South Lake Trailhead for the out and back on the original course. Steady rolling hills on singletrack add up over the distance.
Race-day weather
April in Sonoma County usually brings cool starts and mild afternoons, though exposed hillsides can warm quickly and spring showers can leave the trails muddy.
About the race
The 100K replaced the long-running Lake Sonoma 50 Mile as the headline distance, keeping the same relentless lakeside trails. It is a Western States qualifier, and finishers take home a bottle of wine as their award.
Dates and results by year
FAQ
When is the Lake Sonoma 100K?
The 2027 Lake Sonoma 100K is on Saturday, April 10, 2027.
Where can I find the Lake Sonoma 100K results?
The 2026 results and earlier years are on the results page.
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