Marin Ultra Challenge
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Marin Ultra Challenge
The Marin Ultra Challenge is a trail ultramarathon held on March 13, 2027 in Sausalito, California. The event is organized by Inside Trail Racing and offers two distances.
- 50 Mile
- 50K
Both courses start at the black sand of Rodeo Beach and traverse Marin Headlands, Mt. Tamalpais facing Stinson, and Muir Woods. Terrain includes exposed fire roads with coastal and inland views and tight, technical single track beneath redwood canopy. The 50 Mile course has about 11,000 feet of elevation gain and there is very little trail overlap between laps.
Logistics and aid: the race capacity is 500 runners. Early bib pickup is available at San Francisco Running Company in Mill Valley on Friday, March 12 from 1:00 PM to 6:00 PM; race morning pickup is also provided. Aid stations supply a variety of food and drink and basic first aid; Gu gels are not allowed at Conzuleman, Tennessee Valley, Muir Beach, and Willow Camp aid stations. Skratch Hydration is mixed at 80 to 100 calories per 20 fluid ounces. Runners are encouraged to carry at least one 20 oz bottle. 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).
Timing will be provided by a third party with a small timing fee added to entries. Time limits are 14 hours for the 50 Mile and 10 hours for the 50K; all runners must be off course by 8:30 PM.
Awards and shirts: top 3 cash prizes for the 50 Mile are $1,000, $500, and $250. All finishers receive event medals and age-group awards are given three deep for male, female, and non-binary categories. To be guaranteed a race shirt and size, registration must be completed by February 27, 2027.
Refunds and cancellations: entry fees are non-refundable. A credit equal to 50% of the original fee may be issued if cancellation occurs at least three weeks before the race. The organizer does not offer refunds for last-minute issues and may not refund if an event is canceled for force majeure, though future race credit may be offered at the organizer's discretion. Visit the organization's website for the most recent information.
