Quad Dipsea
Mill Valley, United States • 29 Nov 2025
Quad Dipsea : November 29, 2025
The Quad Dipsea is a trail ultramarathon held in Mill Valley, California. It is the 42nd running and covers 28.4 miles with about 9,000 feet of total ascent. The course is an out-and-back from Old Mill Park to Stinson Beach and back, and then the same route is repeated to complete the quad distance. The route is single-track for much of the course and does not allow shortcuts; runners must remain on the Dipsea Trail for the entire route.
Course, aid, and rules
The course includes many stairs and steep trail sections, with named segments such as Dynamite, The Hogsback, The Rainforest, Cardiac, Steep Ravine, Insult Hill, and The Moors. The route passes through Muir Woods, crosses Redwood Creek, and offers ocean views near the top of Cardiac. Aid stations are located at Cardiac Hill, Stinson Beach, and Old Mill Park (start/finish and the halfway point). Because much of the trail is single track, pacers are not allowed and hiking or trekking poles are not permitted. There are no refunds, rollovers, or exchanges for entries; a wait list is used and the entrant list is finalized by November 20. Visit the organization's website for the most recent information.