Quad Dipsea

The Quad Dipsea is an epic endurance challenge that takes runners through some of California's most breathtaking landscapes. The race begins promptly at 7:30 AM from Old Mill Park, located at the intersection of Throckmorton Avenue and Cascade Way in Mill Valley.
From the outset, participants face a daunting ascent up three flights of stairs towering as high as fifty stories. This initial climb sets the tone for what lies ahead—a relentless journey through rugged terrain that includes steep hills, winding trails, and narrow paths where shortcuts are not allowed.
The course winds its way through an old horse ranch to Windy Gap before descending into Muir Woods via Redwood Creek. The route then ascends again over challenging sections named "Dynamite," "The Hogsback," "The Rainforest," and the notoriously steep "Cardiac." At Cardiac's summit, runners are rewarded with panoramic views of the Pacific Ocean before tackling the technical descent through Steep Ravine.
As the race progresses, participants face another climb up Insult Hill—a short but steep ascent that tests both body and spirit. The final push towards Stinson Beach offers a mix of challenging terrain and stunning coastal vistas. After reaching the beach turnaround point, runners must retrace their steps back to Old Mill Park for an additional lap.
Time limits are strictly enforced: participants have 4 hours and 30 minutes from start time until noon at Cardiac Hill; they then need to reach Stinson Beach by 2:15 PM (6 hours and 45 minutes after the race begins) before completing their final leg within a total window of nine hours.
Aid stations are strategically placed along the route, providing essential support at key points such as Cardiac Hill, Stinson Beach, and Old Mill Park. However, due to the single-track nature of much of the course, pacers and hiking poles are not permitted.
Registration for this event is highly competitive with no refunds or exchanges allowed once entries have been confirmed. Participants on a wait list will be notified if spots become available but must finalize their entry by November 10th.
The Quad Dipsea offers an unforgettable experience that combines physical challenge with natural beauty, making it a bucket-list race for serious trail runners and adventure seekers alike.