Marin Ultra Challenge
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Marin Ultra Challenge : March 14, 2026, Sausalito, CA
The Marin Ultra Challenge is a trail running event in the Marin Headlands, Mt. Tamalpais State Park and Muir Woods, with a start and finish at Rodeo Beach in Sausalito, CA. The event offers the following distances:
- 50 Mile (50.2 miles, 10,550 ft elevation gain)
- 50K (30.8 miles, ~6,000 ft elevation gain)
The event has a capacity of 450 runners across both distances. Live runner tracking will be provided and disposable timing chips are attached to the back of each bib. Time limits are set for each distance and all runners must be off course by nightfall.
Course, aid stations and logistics
Most of the routes use moderately technical dirt trails and non-technical fire roads, with sections of tight single-track and redwood canopy. Hiking or trekking poles are permitted. Major course features include coastal trails, Dipsea Trail, Willow Camp climbs, passages through Muir Woods, and multiple transitions between the Headlands and Mt. Tam.
Aid stations provide a range of food and drinks; Skratch Hydration is mixed to 80–100 calories per 20 oz. Gu gels are not permitted at aid stations on GGNRA property. Drop bags are available at Tennessee Valley (Mile 10.5 and Mile 45.8) and Cardiac (Mile 19.8 and Mile 29.3 for the 50 Mile); pacers may join after the second pass through Cardiac (mile 29.3). Free parking is available near Rodeo Beach; the walk from the Marine Mammal Center lot is about 1/3 mile. This is a cupless event, so runners must carry their own water bottle or reusable cup. Visit the organization's website for the most recent information.
