Marin Ultra Challenge
Sausalito, United States • 14 Mar 2026
Marin Ultra Challenge : March 14, 2026, Sausalito, CA
The Marin Ultra Challenge is a trail ultramarathon event held in the Marin Headlands, Muir Woods, and Mt. Tamalpais area. The event offers two distances and starts at Rodeo Beach. Courses use a mix of moderately technical dirt single-track and non-technical fire roads, with coastal and inland views and redwood-canopied sections. The route includes parts of the Coastal Trail, Miwok, Dipsea, and Willow Camp climbs, and passes Stinson Beach and Muir Beach.
Distances
- 50 Mile - ~50.2 miles, ~10,550 ft elevation gain
- 50K - ~30.8 miles, ~6,000 ft elevation gain
Race logistics and services
The event has a field capacity (450 runners across distances) and uses live runner tracking and chip timing. 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. Aid stations provide a range of foods and drinks and basic first aid items; Gu gels are not allowed at aid stations on certain park property. The race is cupless - runners must carry a reusable cup or bottle. Drop bags are available at Tennessee Valley (Mile 10.5 and Mile 45.8) and Cardiac (Mile 19.8 and Mile 29.3, 50 Mile only); drop bags must be left at the designated area by 6:00 AM. Pacers may join after the second pass through Cardiac Aid Station. Crew access varies by aid station; some require a short hike. Dogs are not allowed on the course; leashed dogs are permitted at Rodeo Beach. Visit the organization's website for the most recent information.