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Ultras · US · KS

Iron Will 100

36 Hour
Registration open
Registration is open.
Race dateSeptember 19, 2026
Start6:00am
Whenin 23 days
First held2022
Free, and always will be. NavRun makes money from race-day planning for runners who want it, never from this. Ultras change constantly, sometimes the morning of. Always confirm with the race director and the official website before you rely on anything here.
Distance does not apply to this race
Climb not checked yet
Descent not checked yet
High point not checked yet
Time limit 36:00:00
Aid stations 0
Started not checked yet
Finished not checked yet
Finish rate not checked yet
The course

Where it goes fixed time

A fixed-time event on the same course infrastructure: run as much of the out-and-back trail as you can in 36 hours. There are no DNFs -- a finisher is credited with the mileage they covered.

The race

What this one is

A 100-mile, 50-mile, 50K and 36-hour ultra on a flat, 75%-shaded river trail outside Junction City, Kansas, run as repeating out-and-back laps from a single start/finish venue. It was built with a 36-hour cutoff and a wide, even trail so runners managing a disability can take part alongside everyone else.

Founder Will Sprouse, an ultrarunner and race director, had a stroke in 2020 that left him with balance and heart-rate problems. After relearning to walk and run, he found that most 100-milers' roughly 30-hour cutoffs no longer worked for his post-stroke pace. He designed the Iron Will 100 around a 36-hour cutoff and a flat, wheelchair/stroller-wide course, and it debuted on September 10, 2022, in his home state of Kansas.

Getting in

Getting in Entry, lottery and what the race asks of you before race day.

Lottery
not checked yet
Lottery opens
not checked yet
Lottery draw
not checked yet
Field cap
not checked yet
Registration
UltraSignup ultrasignup.com
Qualifying
not checked yet
Minimum age
not checked yet
Transfers
not checked yet
Deferrals
not checked yet
Crew access, pacers and drop bags

The rules that shape your day Anything marked "not checked yet" is a gap in what we hold, never a no from the race.

Crew allowed
not checked yet
Vehicles per runner
not checked yet
Pacers
not checked yet
Muling
not checked yet
Drop bags
not checked yet
Cupless
not checked yet
Course marking
not checked yet
Night running
Yes ultrasignup.com
Dogs
not checked yet
Headphones
not checked yet
Crew rules
not checked yet
Pacer rules
not checked yet
Drop bag rules
not checked yet
Cutoff philosophy
not checked yet
Same race, other lines

Other distances and other years

What it looks like out there

Somebody has been out there with a camera the tables say the climb is long. these say what long feels like.

One person has been out there with a camera or a microphone.

These are other people's work and we link straight to them. Watching costs nothing and needs no account. More of them: every race we hold, on film.

Add to this page

What you know every one of these is read by a person before it changes anything

Ran this race? Tell the next runner what you know.

Nobody sees it until we have read it. No account, no sign-in.

Leave blank if it applies to the whole race.

Leave blank if it is not about one particular stop.

Optional. Something like “Cal Street, mile 62 to 78”.

Write it the way you would say it to someone at the start line.

Optional, and it decides nothing. It only tells the next runner where this is coming from.

Optional.

Optional, and never shown on the page. Only so we can ask you a question about this note.

Leave this field blank.

See something wrong or out of date? Suggest an edit.

This changes nothing on the page on its own. Somebody checks it against the race first.

Optional. Filled in for you when you start from a specific line on the page.

Copy it as it appears, so we can find it.

The corrected value.

Required. Where it came from: the race email, the runner manual, what you saw on the day.

Optional.

Optional. A screenshot or a photo of the sign works.

Optional, and it decides nothing.

Optional.

Optional, only so we can come back to you about this correction.

Leave blank if it is about the whole race.

Leave blank if it is not about one particular stop.

Leave this field blank.

Seen a course preview or a film of this one? Send it over.

Somebody watches it before it goes anywhere near this page. What we are after is footage of this course, on the ground. If it would be just as true of any other race, it is not this.

Required. A line is plenty. Where the climbs are, what the footing does, what the last twenty miles look like.

Optional, and it decides nothing.

Optional.

Optional, and never shown on the page. Only so we can ask you a question about this one.

A YouTube link, a race report, a photo gallery, whatever it is.

Optional, and we credit them on the page.

Leave this field blank.

Have the GPX? Send us the link.

We want the address of the file the race publishes, not the file. We download it from there so the page can say where the line came from.

The page or file on the race's own site.

Optional, and only so we can ask you a question about it.

Are you the race director? Get in touch and we'll make it right.

We read every one of these and we write back. Every fact here carries the source it came from, and the way a wrong one gets fixed is a person checking it against what you tell us.

Required, because this is a conversation and we write back.

Tell us what is wrong, out of date, or missing on this page. We read every one of these and we will get back to you.

Optional.

So we know who we are writing back to.

Optional. Director, assistant, comms, whoever you are.

Leave this field blank.

Where this came from. Every fact on this page records its source and when we last checked it: 36 sources for this race. Hover a source link to read the sentence it came from.
11% of what we track for a course is filled in. The rest says "not checked yet" rather than guessing.
See something wrong or out of date? Suggest an edit
Ran this race? Tell the next runner what you know
Got footage of this course? Send us the link
Are you the race director? Get in touch and we'll make it right.
Anything else: [email protected]
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