From big races to Saturday morning group runs—find 10k events and connect with the local endurance sports community.
Annadel Half Marathon/10K/5K
The Annadel Half Marathon, 10K, and 5K
The Annadel Half Marathon is a non-profit fundraising event that, over the past 15 years, has raised significant funds to help make Trione-Annadel State Park a more beautiful place for everyone to enjoy. Thanks to the incredible support of our sponsors, participants, and volunteers, this race has become one of Sonoma County’s premier running traditions — and we’re excited to return in 2026!
The Half Marathon, 10K, and 5K are among the biggest running events in Sonoma County, drawing runners of all levels to the scenic trails of Annadel State Park.
Half Marathon: 4-hour cut-off time
10K & 5K: Great options for walkers and first-time participants
Each participant receives a race medal, a event shirt, and post-race beverages and snacks.
Join us for a day of running, community, and supporting the park we all love!
Protect the Place You Race
In honor of Earth Day (April 22), we’re proud to host a low-waste event with cup-free aid stations, refill options, and a focus on park stewardship — because every mile should leave Annadel better than we found it.
A portion of event proceeds is donated to Trione-Annadel State Park and the Sonoma County Parks Foundation.
Please note that all race registrations are final and non-refundable. We encourage participants to consider purchasing race protection insurance during registration for added peace of mind.
Ready to push your limits and live an unforgettable experience?🤩 Come join the Santa Rosa Marathon! If you're passionate about running, whether you are a sprint enthusiast or an experienced marathoner, there's a distance for every runner: from the 5K to the marathon.🏃♂️
1 in 8 women will be diagnosed with breast cancer in their lifetime.
Cindy is a mother, a wife, a friend who received this diagnosis.
So, we race.
We race for awareness.
We race for the 1 in 8.
We race for the survivors.
We race for Cindy.
We race for breast cancer.
Wind down FeBREWary in Santa Rosa with Beer City Half™! See the sights, run the trails, and drink the brews that have made Santa Rosa famous world-round. Beer City Festival is a full day on a full weekend. Drink local and dig it! (ProTip: Capacity is limited and this event sells out.)
USA Swimming Club. Safe Sport Recognized. 240 members.