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Ultras · US · AZ

Colossal-Vail 50/50

55K · 33.8 miles
Registration open
Race dateDecember 5, 2026
Start7:15am
Whenin 42 days
First held2014

Who's going to Colossal-Vail 50/50?

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 Entry Aid stations 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 The race
33.8 miles
Climb
2,063 ft
Descent
2,072 ft
High point The race
4,200 ft
Time limit
not checked yet
Aid stations
7
Started
not checked yet
Finished
not checked yet
Finish rate
not checked yet
The course

Where it goes out and back · 7 aid stations

Course line from the race's own GPX. Source file. Recorded 2025.

The south out-and-back of the Arizona Trail from La Posta Quemada Ranch to Peaks View and back. 50 Mile runners can drop to this distance and take 55K credit.

Gain is published as 'approximately 2,300 ft. of elevation gain' on the course page and 'almost 2,300 feet' in the 2025 guide; the course page text also says 'almost 3,000 feet of climb'. Not stored as a number because it is approximate and the pages disagree. The race calls the distance '34 miles' in text and 33.8 on the aid chart.

The race

What this one is

An ultra on the Arizona Trail near Vail, 24 miles southeast of Tucson, starting and finishing at Colossal Cave Mountain Park. Two out-and-backs make the 50 Mile and 55K, plus a daytime and a nighttime half marathon. Mostly singletrack on rolling desert. All proceeds benefit the Arizona Trail Association.

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 runazt.org
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
Yes runazt.org
Vehicles per runner
not checked yet
Pacers
No runazt.org
Muling
not checked yet
Drop bags
Yes runazt.org
Cupless
Yes runazt.org
Course marking
Fully Marked runazt.org
Night running
not checked yet
Dogs
not checked yet
Headphones
Not allowed runazt.org
Crew rules
Crew may reach the Gabe Zimmerman (GZ) and Pistol Hill (PH) aid stations and the start/finish, and nowhere else. No crew at Sahuarita Road (SR), Peaks View (PV), La Selvilla (LAS), the north turn-around, or X-9 Ranch Road. Attempts to access these areas will result in the runner being disqualified. (2025 Participant Guide.) runazt.org
Pacer rules
not checked yet
Drop bag rules
Drop bags at Sahuarita Road (SR) miles 11 and 23. Delivered to the start/finish before 6:50 a.m. (2025 Participant Guide.) runazt.org
Cutoff philosophy
One cutoff: Gabe Z (GZ) at mile 28.9 at 4:15 pm (9 hours). Runners must leave the aid station before the cutoff. No finish time limit is published. runazt.org
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 Start
NoneSignal wrong?
 ? ● ? ? ? 4.90
4.90 Gabe Zimmerman (GZ) Southbound
NoneSignal wrong?
 ? ● ○ ? ? 6.10
11.00 Sahuarita Road (SR) Southbound
NoneSignal wrong?
 ? ○ ● ? ? 5.90
16.90 Peaks View (PV) South Turn-Around
NoneSignal wrong?
 ? ○ ○ ? ? 5.90
22.80 Sahuarita Road (SR) Northbound
NoneSignal wrong?
 ? ○ ● ? ? 6.10
28.90 Gabe Zimmerman (GZ) Northbound
NoneSignal wrong?
 4:15pm ● ○ ? ? 4.90
33.80 Finish
NoneSignal wrong?
 ? ● ? ? ? ?
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.

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.

Were you out there? Say which stops a text got out from.

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

Optional, and it decides nothing.

Which stops did a text get out from?

Leave a stop blank if you did not try, or do not remember.

50 Miler

  • Start mile 0.0
  • Gabe Zimmerman (GZ) Southbound mile 4.9
  • Sahuarita Road (SR) Southbound mile 11.0
  • Peaks View (PV) South Turn-Around mile 16.9
  • Sahuarita Road (SR) Northbound mile 22.8
  • Gabe Zimmerman (GZ) Northbound mile 28.9
  • La Selvilla (LAS) Northbound mile 35.5
  • Pistol Hill (PH) Northbound mile 39.1
  • Pistol Hill (PH) Southbound mile 44.3
  • La Selvilla (LAS) Southbound mile 47.9
  • Finish mile 50.1

55K

  • Start mile 0.0
  • Gabe Zimmerman (GZ) Southbound mile 4.9
  • Sahuarita Road (SR) Southbound mile 11.0
  • Peaks View (PV) South Turn-Around mile 16.9
  • Sahuarita Road (SR) Northbound mile 22.8
  • Gabe Zimmerman (GZ) Northbound mile 28.9
  • Finish mile 33.8

13 Miler NIGHT

  • Start mile 0.0
  • La Selvilla (Northbound) mile 2.2
  • Pistol Hill (PH) Northbound mile 5.8
  • Pistol Hill (PH) Southbound mile 7.3
  • La Selvilla (LAS) Southbound mile 10.9
  • Finish mile 13.1

13 Miler

  • Start mile 0.0
  • Gabe Zimmerman (Heading South) mile 4.9
  • Gabe Zimmerman (Heading North) mile 8.7
  • Finish mile 13.6
Optional. Never shown.
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: 88 sources for this race. Hover a source link to read the sentence it came from.
41% 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
Were you out there? Say which stops a text got out from
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.