161.7 kmTrail🇺🇸 Geyserville, United States

Lake Sonoma 100 Mile

Saturday, 17 October 2026In 6 days · Start 05:00

New in 2026: two 50-mile loops of Lake Sonoma singletrack opening with the Pritchett Peaks climb, for over 25,000 ft of climbing in total.

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Facts checked 10 Oct 2026 against aravaiparunning.com.

Elevation gain

7,640 m

Mountain · ↓ 7,640 m

Start altitude

146 m

above sea level, from terrain data

Temp at start

12°C

Peaks around 18°C

Entry fee

≈ $435

Open entry

Finishers

—

typical year

Course

Multiple laps

36h cut-off

Getting thereFly into SMF (Sacramento), about 123 km from the start

Course map

A detailed route is not available for this race yet. The marker shows the race location.

Elevation profile

Mountain: about 7,640 m of climbing and 7,640 m of descent. A detailed profile isn’t available for this race yet.

Race-day weather

At start

12°C

Peak during race

18°C

Humidity

73%

Chance of rain

Wind

6 km/h

Race day in past years

Historical averages for 17 October ±3 days, 2016–2025, from 05:00 for 5 hours (70 days sampled). Source: Open-Meteo / ERA5.

What time could you run here?Adjust your goal time for this course’s hills and typical race-day weather.Race time calculator →

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<a href="https://irun42.com/race/lake-sonoma-100" title="Lake Sonoma 100 Mile on iRun42"><img src="https://irun42.com/badge/lake-sonoma-100.svg" width="300" height="120" alt="Lake Sonoma 100 Mile: course, elevation and race-day weather on iRun42" /></a>