Annadel Half Marathon
Santa Rosa, United States • 18 Apr 2026
Event Overview
The Annadel Half Marathon is a non-profit fundraising event held in Santa Rosa, California. Based at Spring Lake Regional Park, the race utilizes the scenic trails of Trione-Annadel State Park. This long-standing running tradition in Sonoma County supports local park stewardship, with a portion of the proceeds donated to Trione-Annadel State Park and the Sonoma County Parks Foundation.
The event emphasizes environmental sustainability. In honor of Earth Day, the organizers host a low-waste event featuring cup-free aid stations and refill options to minimize the environmental impact on the park.
Distances and Course
Participants can choose from three different distances. The courses take runners through the natural landscapes of Annadel State Park.
- Half Marathon: This distance has a 4-hour time limit.
- 10K: A distance suitable for walkers and first-time participants.
- 5K: A distance suitable for walkers and first-time participants.
Participant Information
All registered participants receive a race medal and an event shirt. After the race, beverages and snacks are provided to runners. Registration is final and non-refundable, though race protection insurance is available for purchase. The venue is located at 5585 Newanga Avenue in Santa Rosa. Visit the organization's website for the most recent information.