Marin Ultra Challenge
Sausalito, United States • 14 Mar 2026
Event details
The Marin Ultra Challenge is a trail running event in Sausalito, California, hosted by Inside Trail Racing on March 14, 2026. Distances offered:
- 50 Mile - 50.2 miles, ~10,550 ft elevation gain
- 50K - 30.8 miles, ~6,000 ft elevation gain
The event is limited in field size (capacity listed as 450 runners). Live runner tracking will be used and disposable timing chips are attached to the back of each bib. Dogs are not allowed on the course; dogs on leash are permitted at Rodeo Beach.
Course and logistics
The courses start at Fort Cronkhite / Rodeo Beach and traverse the Marin Headlands, Mt. Tamalpais, Muir Woods, coastal sections, fire roads, and technical single-track. Most terrain is moderately technical dirt trail and non-technical fire road; hiking or trekking poles are permitted. Drop bags are staged at Tennessee Valley (Mile 10.5 and Mile 45.8) and Cardiac Aid Station (Mile 19.8 and Mile 29.3; Cardiac is passed multiple times by the 50 Mile). Crew can reach most aid stations but must follow posted parking rules; there is no parking at Deer Park and crew must hike about 0.5 miles to Cardiac.
Aid stations supply a variety of food and drinks, including Skratch Hydration (about 80-100 kcal per 20 fl oz), whole fruit, sandwiches, and snacks. Gu Energy gels are not allowed at aid stations located on Golden Gate National Recreation Area property. The event is cupless; runners must carry their own bottle or reusable cup.
Awards and rules
Time limits apply: 14.5 hours for the 50 Mile and 10 hours for the 50K. The top three male and female finishers in the 50 Mile receive trophies, shoes, and cash awards ($500, $250, $150). Top three in the 50K receive trophies and shoes. All finishers receive a custom medal; 50 Mile and 50K finishers also receive a pint glass. Entry fees are non-refundable, with a partial credit policy available three weeks prior to the event. Visit the organization's website for the most recent information.