Angeles Crest 100 Mile Endurance Run
36th Annual
100 Miler
Course changed
The route is not the one it was. Read the race's own notice before you plan. The course has been redrawn for 2026 after Highway 2 storm damage and Eaton Fire trail closures; it now starts and finishes at Loma Alta Park in Altadena, out and back to Mount Hillyer. The lottery for this edition has closed and the waitlist is open.
Race dateOctober 3-4, 2026
Duration2 days
Whenin 24 days
First held1986
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
not checked yet
Climb
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Descent
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High point
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Time limit
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Aid stations
0
Started
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Finished
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Finish rate
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The race
What this one is
The Angeles Crest 100 Mile Endurance Run runs through the San Gabriel Mountains above Los Angeles, one of the first hundred-mile trail races in the country and a Western States 100 qualifier. Wildfire, winter storms, and wilderness designations in the Angeles National Forest have forced the race to change its route again and again since 2020. The 2026 edition is a new out-and-back between Loma Alta Park in Altadena and a turnaround at Mount Hillyer.
AC100 started in 1986 as one of the first five hundred-mile trail races in the country, finishing at the Rose Bowl through 1991, then Johnson Field, and, from 2008 on, Loma Alta Park in Altadena. Fires kept the race from being held in 2002 and 2009, and it moved from September to August starting in 2010. Wilderness expansions along the course forced repeated reroutes through the 2010s, and the Bobcat Fire, together with the COVID-19 pandemic, cancelled the race in 2020 and 2021. The route has changed most years since: an out-and-back to Shortcut Saddle, a finish routed via the Kenyon/Devore Trail bypassing Chantry Flats, and a Wrightwood out-and-back in 2025 after the Bridge and Eaton Fires. Winter-storm damage to Highway 2 closed two more sections in 2026, and for the first time the race starts and finishes at Loma Alta Park itself, out and back to Mount Hillyer.
Getting in
Getting in
Entry, lottery and what the race asks of you before race day.
- Lottery
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Yes
ac100.com
- Lottery opens
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Sept. 19, 2025
ac100.com
- Lottery draw
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Oct. 3, 2025
ac100.com
- Field cap
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not checked yet
- Registration
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UltraSignup
ac100.com
- Qualifying
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not checked yet
- Minimum age
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not checked yet
- Transfers
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No
ac100.com
- Deferrals
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No
ac100.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
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not checked yet
- Vehicles per runner
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not checked yet
- Pacers
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not checked yet
- Muling
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not checked yet
- Drop bags
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not checked yet
- Cupless
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not checked yet
- Course marking
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not checked yet
- Night running
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not checked yet
- Dogs
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not checked yet
- Headphones
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not checked yet
- Crew rules
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not checked yet
- Pacer rules
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not checked yet
- Drop bag rules
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not checked yet
- Cutoff philosophy
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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.
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.
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.
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.
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.
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.
Where this came from.
Every fact on this page records its source and when we last checked it: 37 sources for this race. Hover a source link to read the sentence it came from.
0% of what we track for a course is filled in. The rest says "not checked yet" rather than guessing.
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.
Running this one?
NavRun builds your pacing from your own training, then turns it into a plan your crew can follow: when to leave and where to park.
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