Quad Dipsea
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Quad Dipsea - Mill Valley, CA
Quad Dipsea is a 28.4 mile trail race held in Mill Valley, California. The course packs about 9,000 feet of vertical gain and follows the Dipsea Trail to Stinson Beach and back, then repeats that out-and-back sequence for a total of four legs.
The route starts at Old Mill Park (Throckmorton Avenue, Cascade Way, and Old Mill Street intersection). Within a few hundred yards it climbs multiple flights of stairs and continues up through an old horse ranch to Windy Gap. The course then descends into Muir Woods, crosses Redwood Creek, and ascends trail sections named Dynamite, The Hogsback, The Rainforest, and Cardiac. From there it offers views toward the ocean before dropping through Steep Ravine and the short climb known as Insult Hill, followed by the more level terrain of The Moors toward Stinson Beach.
Aid stations are located at Cardiac Hill, Stinson Beach, and Old Mill Park (start/finish and the halfway point). Due to the single track nature of the course, no pacers are allowed and the use of hiking or trekking poles is not permitted. The event enforces time limits and specific cutoffs. Registration opens August 1, 2026, and a wait list is used to fill cancellations; the entrant list is finalized by November 10. Visit the organization's website for the most recent information.
