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Miwok 100K ultramarathon

MAY 2, 2026 – 5:00 A.M.

The Miwok 100K is one of the most beautiful and iconic trail ultramarathons in the world.

Registration for the 100K and 4 person Team Relay opens on November 9, 2025 at 6am PST/9am EST on RunSignUp!

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  • long distance trail runner participating in the Miwok 100K ultramarathon on the Marin County coast in California long distance trail runner participating in the Miwok 100K ultramarathon on the Marin County coast in California

We believe everyone deserves a shot at something extraordinary. The Miwok100K is about the everyday runner who shows up ready to dig deep on some of the most breathtaking trails around.

The Course

Set in the Marin Headlands just north of San Francisco, Miwok offers 62 miles of gorgeous trails, over 11,000 feet of gain, and nonstop views, from redwoods to ridge lines to crashing coastal cliffs. Learn more about the course.

Who Should Run Miwok?

This race is for runners who:

  • Embrace steep climbs, exposed ridges, and fast-changing weather
  • Have experience with trail ultras and self-supported effort
  • Respect the land and leave no trace
  • Can stay ahead of tight intermediate cutoffs (to ensure safety and meet permit requirements)

You don’t need to be elite. But you do need to be prepared.

What Runners Get

  • A well-marked, scenic, and demanding course
  • Supportive aid stations and a tight-knit trail community
  • A Miwok finisher award to be proud of and ultra-specific goodies
  • A strong community supporting you from training to race day
  • Professional medical care at all aid stations
  • The best crew of volunteers

Registration Info

  • Registration opens: Nov. 9, 2025 at 6 am PST on RunSignUp
  • Race Date: May 2, 2026 at 5 am PST
  • Location: Stinson Beach, CA
  • Field Limit: 400 runners
  • Registration Opens: November 9, 2025, at 6 am PST
  • Time Limit: 15 hours and 30 minutes 

This race sells out quickly. If you’re ready to train, prepare, and take on a challenge, then we’d love to see you at the starting line.

Sustainability, Diversity, Community

For over a decade, the Miwok 100K has led the way in sustainability—pioneering recycling, composting, and a cup-less race since 2013. Leftover food is donated to local shelters.

We proudly support 1% For The Planet  and Leave No Trace , and partner with GU Energy Labs to  TerraCycle all nutrition packaging.

Our Miwok 100K Diversity Initiative, launched in 2020, promotes inclusion of underrepresented groups at the Miwok 100K. To get involved, contact Magda Boulet, RD at miwok100k@gmail.com

Organizations we currently donate & support: Running For A Better Oakland |510 Hikers |Runners for Public Lands |The Coast Miwok of Marin |The Nomadic Adventure Club Ultra Fitness Beyond Imagination

Organizations we have donated in the past: The Edible Schoolyard Project |EatLearnPlay.org | Pinkathon/Breast Cancer Research Foundation

Photography: 2025 Professional Race Photography provided by Tony DiPasquale and Jacob Banta  HERE

Miwok 100K ultramarathon Miwok 100K ultramarathon

Volunteers

Be part of the Miwok 100K magic and join our volunteer crew to help create an unforgettable race experience for runners. Volunteering also earns you priority registration for the next year’s  race by volunteering at least 8 hours this year. Email miwok100K@gmail.com to sign up.

Miwok 100K ultramarathon Miwok 100K ultramarathon

Apparel Collection

The Miwok 100K Apparel Collection is made possible by Pressio.  The team at Pressio delivers unparalleled quality, and exist to elevate athletes through superior performance; and to elevate expectation through an uncompromising pursuit of sustainable excellence. 

Questions?

Email RD Magda Boulet at miwok100k@gmail.com

Miwok 100K ultramarathon Miwok 100K ultramarathon

Sponsors & Partners

Our thanks to the wonderful sponsors and vendors who will be providing cool stuff to our runners. More to come! We’d also like to thank the California State Parks, the Golden Gate National Recreation Area, and Point Reyes National Seashore for their work to manage and maintain the trails on which we love to run!

This year, our donations go to The Cost Miwok of Marin,  Running For a Better Oakland &  Runners for Public Lands

Miwok 100K ultramarathon Miwok 100K ultramarathon

Race Photography

2025 Professional Race Photography provided by Tony DiPasquale and Jacob Banta can be found here.

Miwok 100K ultramarathon

The May 3, 2025 Miwok 100K will be a UTMB 2026 Index Race at the 100K Level. 

WS100 2026 Qualifier