Quad Dipsea

Quad Dipsea is an ultramarathon held in Mill Valley, California, starting at Old Mill Park. The event features four grueling laps along the Dipsea Trail to Stinson Beach and back, totaling roughly 28 miles with about 9,000 feet of elevation gain. Runners confront famous climbs and rugged terrain, including the Windy Gap stairs, Dynamite, The Hogsback, The Rainforest, Cardiac, Steep Ravine, and Insult Hill, with ocean views at the turnaround.

The course stays on single-track and includes aid stations at Cardiac Hill, Stinson Beach, and Old Mill Park. Shortcuts are not permitted; pacers and trekking poles are prohibited. Visit the organization's website for the most recent information.