Quad Dipsea

The Quad Dipsea is a challenging 28.4-mile trail race held in Mill Valley, California, featuring approximately 9,000 feet of vertical gain. The course starts at Old Mill Park and includes steep stairs, rugged hills, and scenic sections such as Muir Woods, Dynamite, The Hogsback, Cardiac Hill, Steep Ravine, and The Moors, with panoramic views of the Pacific Ocean. Runners reach Stinson Beach before turning back, completing the loop four times without shortcuts.

Aid stations are located at Cardiac Hill, Stinson Beach, and Old Mill Park. The race emphasizes a tough, single-track trail experience with no pacers or trekking poles allowed, creating a demanding and scenic ultramarathon event. Visit the organization's website for the most recent information.