Lake Sonoma 100 Miler

Geyserville, United States • 1 Feb 2025

The Lake Sonoma 100 Miler is an exciting endurance running event set in Geyserville, California, featuring a challenging 100-mile course with approximately 27,000 feet of elevation gain. The race emphasizes a festival-like atmosphere, complete with live music, food trucks, and wine tasting at the start/finish area. Participants can also enjoy a unique "Little Baby" backyard run. The event prioritizes runner experience with generous cutoff times, excellent aid stations, and a focus on community engagement, including charity support for the Children of Vineyard Workers Scholarship Fund. The race is designed to be memorable, whether runners face sunny or muddy conditions. Visit the organization's website for the most recent information.

Race information

100 mi
100 Miler
100 mi
100m 4 Person Relay
50 mi
50m 4 Person Relay
Baby Backyard
Visit the organization's website for the most recent information.
Trail runs nearby

A trail race at Bothe Napa Valley State Park on March 21, 2026 offering marathon, half marathon and 10K with a 300 runner limit. Courses use single track loops with one aid station and a six hour marathon cutoff.

Springtime trail races at Lake Sonoma on April 11, 2026 feature a Western States qualifying 100K, a 50K that crosses the Lake Sonoma bridge, and a women-only Trail Sisters half marathon with shuttle service.

A four-distance trail event in Calistoga that follows single track and fire road into the Mount St. Helena area. Routes include technical sections, long aid stretches, drop bag service at Highway 29, and finisher medals and shirts.

UTMB Index

A community fundraiser at Spring Lake Regional Park on April 18, 2026 featuring a half marathon, 10K and 5K. The low-waste event donates a portion of proceeds to Trione-Annadel State Park and includes a medal, shirt and post-race snacks.