Muir Woods Mountain Challenge
Stinson Beach, United States • 18 Jul 2026
Muir Woods Mountain Challenge
The Muir Woods Mountain Challenge is a trail running event held July 18, 2026 at Mt. Tamalpais State Park near Stinson Beach, California. It offers three distances on technical single track and fire-road terrain with substantial elevation change.
- 10K (6.4 miles, 1,950 feet elevation gain)
- Half Marathon (13.1 miles, 3,450 feet elevation gain)
- 30K (18.8 miles, 4,950 feet elevation gain)
The course begins with a steep climb of about 2,000 feet in just over 2 miles up Willow Camp hill. Ridges provide views toward Stinson Beach and the Pacific Ocean along the Coastal Trail. The route includes the Matt Davis Trail, Dipsea Trail, a run through Muir Woods, and the Cardiac Hill summit before descending back to Stinson Beach.
Most of the route is technical dirt trails and fire-roads with long climbs, rocky and rooty descents, steps, and many turns. Hiking or trekking poles are permitted. Courses are marked with colored ribbons and additional signs; blue ribbons indicate wrong way and should not be followed.
Aid stations provide a range of energy foods and drinks such as gels, Stroop-Waffles, trail mix, potato chips, PB&J, Coke, water, Skratch hydration, and fruit. Runners are strongly encouraged to carry at least one 20 oz bottle. This event is cupless so runners must carry their own bottle or reusable cup; reusable cups will be available for purchase for $5. Drop bag service is not available.
The event has a 300 runner capacity and uses professional chip timing with disposable chips attached to the back of bibs. There is a 6.5 hour time limit for the Half Marathon and 30K. Parking is available free in the Stinson Beach Day Use Area. Dogs are allowed at Stinson Beach on leash but are not permitted on Mt. Tam trails. To guarantee a race shirt size, registration must be completed by July 6, 2026. Visit the organization's website for the most recent information.