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  • race info
    Miwok 100K Ultramarathon
  • race info
    Miwok 100K Ultramarathon

Runner Tracking – May 6, 2023

The Miwok 100K is professionally chip-timing by Negative Split Racing, with timing mats at various locations along the course.

2023 Tracking Link: 

Rules & FAQ


  1. No littering.
  2. Runners must use the bathrooms/outhouses at all of the aid stations when nature calls. Runners violating the “no poop in the woods” policy are subject to disqualification (pee is okay). There are park rangers on the course.
  3. Sale or transfer of a bib number = permanent disqualification. Wearing someone else’s bib number is cheating and both parties will be permanently disqualified.
  4. Any form of aid or crewing outside of “crew-yes” aid stations = disqualification.
  5. No course cutting, including switchbacks. All runners must cross the bridge and enter Muir Beach aid station outbound and inbound.
  6. Runners must respect all cutoffs, and obey race officials, park officials, and CHP officers.
  7. Harassment of any kind – verbal, physical, sexual, electronic – will result in immediate removal and disqualification from the event, with forfeiture of all fees paid.
  8. The Miwok 100K does not tolerate discrimination on the basis of age, color, ethnicity, gender, handicap, national origin, race, religion, or sexual orientation, by any runner, crew, volunteer, or other person associated with the event. Please contact the Race Director as soon as possible if you experience or observe harassment or discrimination.
  9. PEDs – Using performance enhancing drugs is cheating. Boom – automatic DQ, forever. We reserve the right to drug test participants on a random basis.
  10. Runners do not have right-of-way over other trail users. As the Park Service puts it, “Any pushing, shoving, touching, etc. by any race participant of other park visitors can be considered an assault (by law) and can be enforced as such by park staff. Any race participant involved in any such incident will be disqualified from the event. Additionally, all race participants, including pacers, agree to indemnify all event organizers/volunteers against any claims arising from any such incident.”  Be respectful of everybody as you stoke along the single-track (my 90-year-old mom often hikes out here; be careful and kind when passing anyone on the trail.)


    Will there be cups at the aid stations?

    No, please bring your own cup for use at aid stations; there will be no paper cups available. This has worked great for the past decade, preventing over 4,000 cups from going into the landfill each year. Find a cup now and practice carrying and drinking from it. We will have cups at the finish area, because you will be too tired to get up and refill the one you brought with chocolate milk.

    What if there are last-minute course changes?

    Any course changes will be posted here, and announced through social media, and emails, as timing allows.

    What will the weather be like?

    The weather will be “perfect”: Race day can be hot and sunny, cool and foggy, drizzling, torrential, muddy or a combination of ALL of the above! Sunscreen is advisable; so is a light jacket. And a hat.

    Do I need a headlamp?

    YES. It will be pitch dark when you start so you’ll need a headlamp or decent flashlight for the first 75 minutes up the trail, since dawn is not until 6:00-ish. Put your name on it (duct tape) before race day. We’ll have a “light box” at Muir Beach for you to drop it in. The headlamps/lights will be near the goodie bags at the finish area for you to retrieve yours. Do not drop a valuable light into the light box; put it in your drop bag at TV.

    What’s the final cutoff?

    You have 15 hours and 30 minutes (8:30 p.m., due to Park Regulations) to get the job done, and must abide by cutoffs enforced by aid station personnel. No early starts are permitted.

    Are poles allowed?

    Poles aren’t super useful on the Miwok terrain, but they are allowed. However, you must carry them from start to finish if you choose to bring them. No poles are allowed in dropbags, and your crew cannot take them from you or give them to you mid-course.

    Poison Oak? Bees?

    If you have a reaction to poison oak or bees (other than the usual: Run Away!!!), please bring medication as these Elements of Nature have been known to be found outdoors. We do offer a Tecnu washing station at the Finish for you to remove the poison oak oils before heading home.

    Can I sleep in my car at Stinson pre-race?

    Stinson Beach is such a cool place that hundreds of people – surfers, hikers, travelers, runners – would camp out there in their cars year-round if it were allowed. It is illegal to sleep in your car on any of the streets in Stinson.