A trail runner on a grassy ridge above a sea of clouds

Miwok 100K

The Miwok 100K is a 100 km ultra with 3,597 m of vertical gain starting in Stinson Beach, California. It covers the singletrack of the Marin Headlands and Mount Tamalpais, just north of San Francisco.

Prepare for Miwok 100K

A plan built from your answers and your race date.

trail training plan

The Miwok 100K takes place north of the Golden Gate, on the trail network of the Marin Headlands and Mount Tamalpais. The route starts in Stinson Beach and mixes open ridgelines above the Pacific, wooded canyons and coastal singletrack, with repeated views over San Francisco Bay. The footing is mostly runnable, but the climbs come one after another with little flat recovery.

The race is a long-standing fixture of the Bay Area ultra scene. It offers a single distance, the 100K, so the whole field shares the same course and the same day.

The formats

One format only.

Format	Distance	Vertical gain
100K	62 mi	3,597 m

Organizer information, checked on September 21, 2026 · miwok100.org

When to start

At this distance, a build usually runs 12 to 24 weeks. The 2027 date is not published, so counting back from May puts the start around November 9, 2026.

These ranges are working conventions, not a research finding — no trial has compared plan lengths against each other. What matters more is that the plan was built for the weeks you actually have, rather than shrunk down from a longer one.

How to choose your start date

When to start

November 9, 2026

→ February 1, 2027

Worth reading before you enter

Races and distances Trail distances: what changes off the road Distance stops being the useful number. What decides a trail race is how long you are out, how much you climb, and how much the descents have wrecked your legs by the end. Read Training Eating and drinking: what’s proven, what isn’t This is where confident advice most often runs ahead of the evidence. Some of it is well tested. Some is opinion wearing a number. And one common habit can kill you. Read Races and distances When to start preparing your race Most plans fail before the first session, because the block started too late and everything had to be squeezed. Counting back from the date is the dullest and most useful thing you will do. Read

Questions

What is the date of Miwok 100K in 2027?

The date of Saturday, May 1, 2027 is going around for Miwok 100K, in Stinson Beach, but the organizer has not confirmed it. Check their website before you commit.

How hard is the Miwok 100K course?

The Miwok 100K covers 100 km with 3,597 m of vertical gain across the Marin Headlands and Mount Tamalpais. The relentless sequence of climbs and descents makes it demanding, even though most of the trail is runnable.

How should I train for the Miwok 100K?

Stack four to six hour long runs on rolling trail, practice sustained downhill running on dry singletrack, and test your race nutrition in training. Previous experience over 50 to 80 km makes pacing the day much easier.

Other races

This list keeps growing; it draws no line. A race that is missing is prepared for in exactly the same way.

Honolulu · United StatesUltra HURT 100 Jan 16 Its five-loop, 20-mile-per-lap format carries a famously high drop-out rate. Bandera · United StatesUltra HOKA Bandera Endurance Trail Race January The HOKA Bandera Endurance Trail Race is a trail and ultra weekend held in Bandera, Texas, inside the Hil Moab · United StatesUltra Moab 240 Endurance Run January 7 km ultramarathon with 9,620 m of vertical gain, run as one continuous loop out of Moab, Utah. It is par Your race is not here? Tell us about your race You can prepare for it all the same. Any race, anywhere, and even a goal without a race.

Your race is on the calendar. Your plan should be too.

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