Annadel Half Marathon

APR
18
2026
Run for a cause at the Annadel Half Marathon in Santa Rosa's Spring Lake Regional Park. Choose from a half marathon, 10K, or 5K on scenic trails, with proceeds supporting Trione-Annadel State Park. It's a low-waste event featuring a race medal, shirt, and post race refreshments.
Sat 18 Apr 2026
Half Marathon 10 kilometers 5 kilometers

Always double-check with the organizer's website! This page may contain affiliate links.

Annadel Half Marathon

The Annadel Half Marathon is a non-profit fundraising event. It takes place in Santa Rosa, California at Spring Lake Regional Park. The event includes three race distances: a half marathon, a 10K, and a 5K.

The half marathon has a 4-hour cut-off time. The 10K and 5K are noted as options for walkers and first-time participants. Each participant receives a race medal, an event shirt, and post-race beverages and snacks.

A portion of the event's proceeds is donated to Trione-Annadel State Park and the Sonoma County Parks Foundation. The event is described as low-waste with cup-free aid stations and a refill option, in honor of Earth Day. Visit the organization's website for the most recent information.

Half Marathon
Half Marathon
10 km
10k
5 km