Marin Ultra Challenge
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Event overview
The Marin Ultra Challenge is a trail running event in Sausalito, CA, held on March 14, 2026. Distances offered are:
- 50 Mile - 50.2 miles, 10,550 ft elevation gain
- 50K - 30.8 miles, ~6,000 ft elevation gain
The event uses trails in the Marin Headlands, Mt. Tamalpais State Park, and Muir Woods, with the start and finish at Rodeo Beach. The event has a capacity of 450 runners across both distances. Timing and live tracking will be provided by an external timing service.
Course and logistics
Courses include a mix of technical single-track and non-technical fire roads with substantial climbing and descending. There is minimal trail overlap between routes. Time limits are 14.5 hours for the 50 Mile and 10 hours for the 50K; all runners must be off course by 8:30 PM. The event is cupless; runners must carry their own cup or bottle. Organizers recommend carrying at least one 20 oz bottle. Headlamps are advised for runners expected to be out after sunset.
Drop bags are available at Tennessee Valley (Mile 10.5 and Mile 45.8) and Cardiac aid stations (50 Mile passes at Mile 19.8 and Mile 29.3). Crew and pacers may access aid stations subject to posted parking rules; pacers may join after the second pass through Cardiac Aid Station.
Aid, awards and shirts
Aid stations provide a range of foods and drinks, Skratch Hydration, and basic first aid supplies; Gu gels are not available at certain GGNRA aid stations. Top 3 overall 50 Mile finishers receive cash prizes ($500, $250, $150) and shoes; 50K top finishers receive trophies and entries to a future event. All finishers receive medals and race-branded items. Race shirts are tri-blend performance tees; guaranteed sizes require registration by February 28, 2026. Visit the organization's website for the most recent information.
