Mt. Tam Wild Boar Half Marathon
Mill Valley, United States • 25 Apr 2026
The 38th annual Mt. Tam Wild Boar Half Marathon and 10K takes place in Mt Tamalpais State Park, located in Mill Valley, California. The race course utilizes a combination of paved roadways and dirt single-track trails along the coastal ridge. Runners start at Rock Springs and follow Ridgecrest Boulevard along the Bolinas Ridge, which separates East and West Marin County. The route offers views of the Pacific Ocean, Bolinas Lagoon, and the Marin County watershed.
The event provides two distance options:
- Half Marathon
- 10K
The 10K course turns at Willow Camp Trail and returns to Rock Springs via the Coastal Trail. The Half Marathon continues along Ridgecrest Boulevard to Bolinas-Fairfax Road before also returning via the Coastal Trail. Both courses have a three-hour cut-off time. Aid stations are situated at mile 5 for the 10K, and at miles 2.35, 7, and 12 for the Half Marathon.
The event is limited to 300 participants. Registration is open to both adults and youth under 17 years of age. All participants receive a T-shirt, and finishers of the Half Marathon receive a medal. Performance awards are mailed to the top three male and female finishers in each age group. For safety reasons, headphones and other audio devices are not permitted on the course due to narrow trails and steep drop-offs. Parking is available at the Rock Springs Parking area within the state park. Visit the organization's website for the most recent information.