Loading...
Ultras · US · ID

IMTUF 100 - Idaho Mountain Trail Ultra Festival

15th Annual IMTUF100
IMTUF 20 Mile · 20 miles
Ran · this year's race is done.
As of late Aug 2026 (about 3-4 weeks before race day): the 100 Mile shows 203 registered entrants on UltraSignup against the RD's stated field cap of 200, with an active 76-person waitlist. The 20 Mile shows 38 of its 75-entrant cap and no waitlist (still open). Neither race has run yet for 2026.
Race dateSeptember 20, 2026
Start9:00am
When26 days ago
First held2012

Who's going to IMTUF 100 - Idaho Mountain Trail Ultra Festival?

I'm running itPlan your weeks and your aid station times I'm crewingWhen to leave, where to park, at every stop I'm pacing or cheeringAsk your runner for their Out Here link

Free. You can start with nothing.

Official website Aid stations Crew access Notify me if this race changes
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 20 miles
Climb 5,000 ft
Descent 5,000 ft
High point not checked yet
Time limit 9:00:00
Aid stations 4
Started not checked yet
Finished not checked yet
Finish rate not checked yet
The course

Where it goes loop · 4 aid stations · rust marks a stop your crew can reach

No official GPX on file yet. These are the aid station coordinates, not the trail. Have the GPX? Send us the link.

A 20+ mile loop from Jug Mountain Ranch sharing the 100 Mile's opening climb over Ladybug and Jughandle Mountains and down the talus to Louie Lake (the first ~11 miles), then right onto the Louie Lake Loop Trail up and over Twin Peaks Pass, descending to Boulder Lake, along the Boulder Lake shoreline trail and across the Boulder Lake Dam to Boulder Lake Trailhead Aid Station (with a short out-and-back to the aid station itself), then the same final miles as the 100 Mile course back to the finish at Jug Mountain Ranch.

"A tough and beautiful 20 mile mountain race. Jughandle Mountain is the towering peak southeast of McCall... defended by steep and unrelenting cross country slopes and a crown of granite talus fields." Shares the 100 Mile's mandatory WALK (no running) zone through the Jughandle talus. Self-sufficiency is emphasized: only one well-manned aid station (Boulder Lake) plus one unmanned water stop; runners are told to pack as for a long unsupported training run. Course records are not separately tracked/published for this distance in the sources checked.

The race

What this one is

A 100-mile mountain loop race starting and finishing at Jug Mountain Ranch near McCall, Idaho, crossing multiple 7,000-8,300+ ft passes in the Salmon River Mountains with roughly 22,000 ft of climbing on rugged, TUF footing. A companion 20-mile race over Jughandle Mountain (the IMTUF 20 Mile) starts the following morning from the same venue. Both races together make up the Idaho Mountain Trail Ultra Festival (IMTUF).

First run in 2012; 2026 is the 15th running. The course ran clockwise in 2012 and switched to counter-clockwise in 2013. The current 'Supercourse' routing was introduced in 2020 and has been trimmed slightly at the start/finish in most years since (most recently losing about 1.5 miles in 2025 due to logging activity in the area); the 2026 course is planned to be identical to 2025. Since 2012 the race has run with permission from the Payette National Forest McCall Ranger District and the Idaho Department of Lands.

Getting in

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

Lottery
No imtuf100.blogspot.com
Lottery opens
not checked yet
Lottery draw
not checked yet
Field cap
75 docs.google.com
Registration
UltraSignup ultrasignup.com
Qualifying
not checked yet
Minimum age
not checked yet
Transfers
No imtuf100.blogspot.com
Deferrals
No imtuf100.blogspot.com
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
Yes docs.google.com
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
Fully Marked docs.google.com
Night running
No docs.google.com
Dogs
Not allowed imtuf100.blogspot.com
Headphones
not checked yet
Crew rules
not checked yet
Pacer rules
not checked yet
Drop bag rules
not checked yet
Cutoff philosophy
Single finish-line cutoff, no intermediate cutoffs published: "Cutoff: 6:00 PM- same as for the IMTUF100 Mile. 9 hours is plenty of time for anyone to go 20 miles." imtuf100.blogspot.com
Aid stations

Every stop, and what you get there ● yes   ○ no   ? nobody has checked   – does not apply to this race

Mile Station Cutoff Crew access Bag Pacer Med To next
0.00 Jug Mountain Ranch (Start)
4,955 ft
 ? ● ? ? ? 7.00
7.00 Unmanned water stop (Jug Meadows) ? ○ ○ ? ? 8.00
15.00 Boulder Lake Trailhead
6,234 ft
 ? ● ? ? ? ?
? Jug Mountain Ranch (Finish)
4,955 ft
 6:00pm ● ? ? ? ?
Driving your crew

Getting your people there 1 stop with directions the race published.

Boulder Lake Trailhead mile 15.00

Same as the 100 Mile's leg 7 (Lake Fork Aid to Boulder Lake Aid Station): via Rt 55 south to Elo Rd/Farm-to-Market Rd, then LEFT on Boulder Lake Road (Forest Road 403).

docs.google.com
Same race, other lines

Other distances and other years

Other distances
IMTUF 100 Mile (100 Mile)
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.

Nobody has been out there with a camera or a microphone yet. A gap means nobody has found it, not that it is not out there. Seen a course preview or a film of this one? Send us the link.

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: 102 sources for this race. Hover a source link to read the sentence it came from.
37% 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]

Ultras change. We will tell you when this one does.

Cutoffs move, races get postponed, lotteries open and close. We read the race's own sources and record where every fact came from. Put your email in and we will send you what changed, and where we read it.

No account, and nothing to cancel.

What happens to your email. Nothing else. I do not sell it, and I will not send you anything except this race changing. One click gets you out.

I keep this catalog because the information is scattered and hard to trust. Telling you when it moves is the same job.

Ultras change. We will tell you when this one does.

Cutoffs move, races get postponed, lotteries open and close. We read the race's own sources and record where every fact came from. Put your email in and we will send you what changed, and where we read it.

No account, and nothing to cancel.

What happens to your email. Nothing else. I do not sell it, and I will not send you anything except this race changing. One click gets you out.

I keep this catalog because the information is scattered and hard to trust. Telling you when it moves is the same job.