2026 Marin Ultra Challenge

The 2026 Marin Ultra Challenge will take place on Saturday, March 14, 2026, in Sausalito, California, with the start and finish at Rodeo Beach, located at 11050 Mitchell Road. The event will traverse the scenic and rugged terrain of the Marin Headlands, Muir Woods, and Mt. Tamalpais State Park, offering runners a challenging course through coastal headlands, redwood forests, and fire roads. The weather in Sausalito on this date is expected to be mild, with partly cloudy skies and temperatures ranging between 50°F and 60°F, making it ideal for trail running. Participants can expect a well-supported, scenic, and demanding race experience across two distances: 50 miles and 50 kilometers.

What distances are available for this event?

• →50 Mile race
• →50K race

What are the start times for the event?

• →50 Mile: 6:30 AM
• →50K: 7:00 AM

What are the time limits for each distance?

• →50 Mile: 14 hours
• →50K: 10 hours
• →All runners must be off course by 8:30 PM

What is the race capacity?

• →The event has a total capacity of 500 runners across all distances

What is the race registration status?

• →The event is currently sold out as of February 14, 2026, with a waitlist that closes on March 8, 2026

What are the key aid station locations?

• →Tennessee Valley Aid Station: Mile 10.5 and Mile 45.8
• →Cardiac Aid Station: Mile 19.8 and Mile 29.3 (for 50 Mile runners only)

What aid station provisions are available?

• →Hydration: Water, Skratch Hydration Mix, Coke, Ginger Ale
• →Food: Gu Energy gels (not allowed at GGNRA aid stations), chews, Stroopwafels, trail mix, pretzels, chips, M&M's, bananas, watermelon, tangerines, salt tablets
• →First Aid: General supplies and Salt-Stick tablets (no anti-inflammatory meds)

What race support services are available?

• →Timing partner: ultralive.net (live tracking, splits, aid station tracking) with a $3 fee included in entry

What awards and swag are given to finishers?

• →50 Mile Finishers: Custom medal, Boco Trucker Hat, and top 3 M/F receive custom trophy and cash prizes
• →50K Finishers: Custom medal, printed drinking glass with race logo, and top 3 M/F receive custom trophy and entry credit
• →Age Group Awards: Medals for 3 deep in each category (13 & under, 14-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70+)
• →Dead Last Finisher (DLF): Custom award for each distance

What is included in the race shirt?

• →District Perfect-Tri tri-blend performance tee (UPF 30, moisture-wicking) with guaranteed size if registered by February 28, 2026

What volunteer opportunities are available?

• →Volunteers receive a custom "MUC Trail Support" shirt, free race-day food, and credit toward future Inside Trail Racing events
• →Apply via online volunteer form

What are the registration policies?

• →Entry fees are non-refundable
• →50% credit toward future Inside Trail Racing events if cancellation is received ≥3 weeks pre-race
• →No credits for cancellations within 3 weeks of race or for injuries/emergencies
• →No transfers or deferrals to other runners
• →No refunds for course modifications due to trail work, closures, or permitting agency requirements
• →Races proceed in rain or heat; no cancellations for weather alone
• →If ITR cancels the event entirely (force majeure), no refunds; credits/deferrals at ITR discretion
• →50/50 Challenge: Combine Monterey Ultra 50 Miler + Marin Ultra Challenge 50 Miler for commemorative Craft Sportswear hoodie and leaderboard placement. Registration via Monterey Ultra. Cancellation for credit must be ≥3 weeks before either event

What are the important deadlines?

• →February 28, 2026: Last day to guarantee race shirt size
• →March 8, 2026: Final date for waitlist invitations (no race-day waitlist)
• →March 14, 2026: Race day — Start/Finish at Rodeo Beach, Sausalito, CA