Quad Dipsea

Quad Dipsea : Mill Valley, CA

The Quad Dipsea is a 28.4 mile trail event in Mill Valley, California, with about 9,000 feet of ascent. The route uses the Dipsea Trail and includes extended stair sections, singletrack, forested climbs, coastal grasslands, rocky descents, and beach approaches.

The course starts at Old Mill Park and heads through steep stair climbs and an old horse ranch to Windy Gap, then descends into Muir Woods and crosses Redwood Creek. Runners proceed through trail sections named Dynamite, The Hogsback, The Rainforest, and Cardiac. At the top of Cardiac there are panoramic ocean views before the route drops through Steep Ravine and up the short but steep Insult Hill, then follows The Moors toward Stinson Beach. Participants turn at Stinson Beach and return to Old Mill Park via the same route, and that round trip is repeated to complete the full distance.

Aid stations are located at Cardiac Hill, Stinson Beach, and Old Mill Park (start/finish and the halfway turnaround). Cutoff limits are given as elapsed times: 4 hours 30 minutes to the halfway turnaround, 6 hours 45 minutes to depart Stinson Beach for Lap 4, and 9 hours to finish.

Due to singletrack sections, pacers and hiking or trekking poles are not permitted. Registration opens August 1, 2026. There are no refunds, rollovers, or exchanges; a wait list is used and the entrant list is finalized by November 10th. Visit the organization's website for the most recent information.