Javelina Jundred - Jackass 31K - Elevation Profile, Aid Stations and Cutoffs
- McDowell Mountain Regional Park, Arizona, USA
- 31.2 km
- 355 m D+
- 3 aid stations
Map, checkpoints and cutoffs Map · checkpoints · forecast opens Oct 22 Race-day forecast is live
Race-day conditions
Weather, daylight and your arrival time at all 5 checkpoints, set to the 17:30 start.
- Start
- 17:30
- Daylight at the start
- 06:44-17:36
- Aid stations
- 3
Course profile
McDowell Mountain Regional Park, Arizona, USA
- Distance
- 31.2 km
- Elevation
- +355 m -355 m About 11 m of climb per km
Next edition Sat 31 Oct 2026 · 17:30
- Start
- Sunset 0h06 after the start
- Winner ~1h60 1h60 after the start
- Median finisher 2025 median 4h51 after the start
- Cutoff 8h30 after the start
A median finisher runs 4h44 in the dark.
Javelina Jundred - Jackass 31K is a 31.2 km (about 19 miles) ultra-trail with around 355 m of elevation gain, starting in McDowell Mountain Regional Park, Arizona, USA. The overall cutoff is 8 hours 30 minutes. That is 11 m of climbing per kilometre. Javelina Jundred has 3 races, from 31.2 to 161 km; this one ranks 3 of 3 by distance and 3 of 3 by climbing per kilometre.
The biggest climb between checkpoints gains around 250 m from Coyote Camp (km 6.4) to Jackass Junction (km 16.9). The steepest sustained section on the elevation profile averages about 3% over roughly 2 km around km 7. The published checkpoint list has no crew-access points - check the official runner guide for assistance rules.
Data is approximate and courses change between editions - always verify against the official race guide.
Other distances at Javelina Jundred
| Race | Distance | D+ | Cutoff | Next start |
|---|---|---|---|---|
| Javelina Jundred | 161 km | 1,919 m | 30h00 | Oct 31, 2026 |
| Javelina 100K | 98.3 km | 1,206 m | 29h00 | Oct 31, 2026 |
| Jackass 31K (this page) | 31.2 km | 355 m | 8h30 | Oct 31, 2026 |
Plan against the cutoffs
Enter a goal finish time and see estimated arrivals vs checkpoint cutoffs.
Estimate your finish
One Strava connection reads your last 90 days and estimates your finish on this course. Free, no plan needed.
Course math
Four numbers worked out from this course's distance, elevation and checkpoints.
TrailMath effort-km
37 effort-km
Below 50 effort-km the model quotes no reference time.
Distance + gain ÷ 100 + loss ÷ 200, beside ITRA's gain-only km-effort. Model TM1.0.
How TrailMath works →UTMB Index category
20K
34 km-effort (distance + gain ÷ 100). Calculated from the course figures, not an official classification.
Estimate your UTMB Index → ITRA and UTMB indexes explainedBiggest climb section
+250 m
Coyote Camp → Jackass Junction · km 6.4–16.9
The largest gain between two checkpoints, not one continuous climb.
Biggest descent section
−215 m
Jackass Junction → Rattlesnake Ranch · km 16.9–25.3
The largest loss between two checkpoints. ITRA's km-effort ignores descent; TrailMath counts it: 37 km-effort.
Open in GPX Explorer →Share this race
Cards sized for Instagram and Strava.
Javelina Jundred - Jackass 31K · 2025
Finish times, 2025 edition
212 runners started. 211 came back. Half of them took longer than 4:50:31. That left the median finisher 3:39:29 inside the 8h30 cutoff.
Median finish
4:50:31
Half of the 211 finishers were still out there at this point.
3:39:29 in hand before the 8h30 cutoff
The start line
99.5%
211 of 212 starters made it; 1 did not.
still moving when a cutoff closed
stopped by choice or by the medics
Men and women
Two medians on the same scale. The bars run from the start to the cutoff, so the gap between them is the gap in time.
Men
4:21:30
median finish; average 4:40:24
79 finishers, 37% of the field
Women
5:04:25
median finish; average 5:19:31
128 finishers, 61% of the field
0:42:55 separates the two medians, across 79 men and 128 women.
Finish time by age group
Every track runs from the start to the 8h30 cutoff, so the empty part of a bar is the time that group's median finisher still had. Men and women are drawn on the same scale.
| Age | Median finish | Median against the cutoff | Finishers |
|---|---|---|---|
| U20 | - | 2 - too few finishers to publish a time | |
| 20-29 | 4:10:41 | 12 - small sample, read with care | |
| 30-39 | 3:49:37 | 17 - small sample, read with care | |
| 40-49 | 4:32:50 | 21 | |
| 50-59 | 4:31:25 | 20 | |
| 60-69 | 5:01:59 | 6 - small sample, read with care | |
| 70+ | - | 1 - too few finishers to publish a time |
| Age | Median finish | Median against the cutoff | Finishers |
|---|---|---|---|
| 20-29 | 5:11:29 | 9 - small sample, read with care | |
| 30-39 | 4:36:31 | 27 | |
| 40-49 | 5:15:04 | 38 | |
| 50-59 | 5:24:24 | 32 | |
| 60-69 | 5:00:10 | 20 | |
| 70+ | - | 2 - too few finishers to publish a time |
Full bar: 20 finishers or more. Tick alone: fewer than 20, too few for a median to say much. The shaded row is the biggest group.
Where the finishers came from
96% of the finishers came from United States alone.
| Nation | Finishers | Share |
|---|---|---|
| United States US | 203 96.2% | |
| Canada CA | 6 2.8% | |
| Mexico MX | 2 0.9% |
Bar length is against the largest nation. The smallest counts are drawn at a minimum visible width, so their bars are not to scale.
Edition by edition
Every edition we have recomputed in full, newest first. The course, the weather and the field change from year to year, so a slower edition is not a harder one.
| Edition | Distance run | Starters | Finishers | Finish rate | Median finish |
|---|---|---|---|---|---|
| 2025 Latest | - | 212 | 211 | 99.5% | 4:50:31 |
| 2024 | - | 202 | 195 | 96.5% | 4:54:44 |
| 2023 | - | 181 | 180 | 99.4% | 4:27:45 |
How these numbers were computed
These are times for runners who finished. They exclude everyone who started and did not, so they describe how long finishing took, not how long the race takes. Bands with only a handful of finishers move a lot from one edition to the next.
We plot the median, not the average. A handful of very quick runners drags the average well below the time half the field actually beat, so the median is the honest number to plan against.
Nationality here shows who travels to this race, not who runs it best. That alone is why a host nation tops almost every list.
Computed from the full official results, verified October 29, 2026 - Official results
Ask the course
Ask Jackass 31K anything about climbs, pacing, crew or cutoffs.
Answers come from this course's data, your plan and your training.
Which climb should I respect most?
Coyote Camp to Jackass Junction: +250 m over 10.5 km, from km 6.4. Hike the steep sections at an effort you could hold for hours - the race is decided after this climb, not on it.
Is 4h a realistic finish for me?
4h would put you in the faster half of 2025 finishers - the median was 4:50:31. It means holding 7:42/km overall.
The assistant answers that once it can see your training.
Build your Jackass 31K plan and your question is the first thing waiting in the TrailMath Assistant. Your first 5 questions are free, no card.
Build my Jackass 31K plan14 days of Premium included.
To answer this for you, the Course Assistant uses your training and your race plan.
Example answer
Your long runs peak at 10 km, so the plan builds to 4-hour long runs.
14 days of Premium included.
Try asking Jackass 31K
Ask anything - we'll open your Jackass 31K plan with your question ready.
Loading the Course Assistant
Race-ready pack
The training is done. The race plan is not.
With 2 days to go, no session will add fitness - a hard one only adds fatigue. What still changes your finish is your margin at each barrier, how you fuel each leg and how rested you arrive.
2 days to the startSat, Oct 31 · 17:30 MST
Pace and fuel, checkpoint by checkpoint
| Checkpoint | km | Barrier | You | Fuel |
|---|---|---|---|---|
| Coyote Camp6.4 km · +95 m | 6.4 | In the app | ||
| Jackass Junction10.5 km · +250 m | 16.9 | In the app | ||
| Rattlesnake Ranch8.4 km · +5 m | 25.3 | In the app | ||
| Javelina Jeadquarters5.9 km · +5 m | 31.2 | Sun 02:00 | In the app | In the app |
A barrier is a cut-off to clear, not a pace to aim for: race on effort, and expect the later legs to be slower.
Fuel by the hour, not by the kilometre - each leg is time between aid stations. Race on the fuel you trained with: nothing new this week.
Arrive fresh
- SEasy
- MEasy + strides
- TRest
- WEasy
- TRest
- FShakeout
- RaceRace
Easy · Easy + strides · Rest · Shakeout
Shape only: the app sets each day's session from your recent load.
Your days, one by one
Your Jackass 31K race plan
Your split to every barrier at your pace, your fuelling leg by leg, and your race week day by day. Jackass 31K is already filled in.
Aid stations and checkpoints
| Checkpoint | Km | Cumulative gain (m) | Cumulative loss (m) | Cutoff |
|---|---|---|---|---|
| Start - Javelina Jeadquarters | 0 | 0 | 0 | - |
| Coyote Camp | 6.4 | 95 | 25 | - |
| Jackass Junction | 16.9 | 345 | 50 | - |
| Rattlesnake Ranch | 25.3 | 350 | 265 | - |
| Javelina Jeadquarters (Finish) | 31.2 | 355 | 355 | Sun 02:00 |
Data is approximate and courses change between editions - always verify against the official race guide. Source: official race guide, verified October 29, 2026 - Official race website
FAQ
How much elevation gain does Javelina Jundred - Jackass 31K have?
Javelina Jundred - Jackass 31K has around 355 m of cumulative elevation gain and 355 m of loss over 31.2 km.
What is the cutoff time for Javelina Jundred - Jackass 31K?
The overall Javelina Jundred - Jackass 31K cutoff is 8 hours 30 minutes, with intermediate time barriers at major checkpoints. Winning times are typically around 2 hours.
How long is Javelina Jundred - Jackass 31K?
Javelina Jundred - Jackass 31K covers approximately 31.2 km (about 19 miles), starting in McDowell Mountain Regional Park, Arizona, USA.
How many aid stations does Javelina Jundred - Jackass 31K have and which allow crew?
The checkpoint table lists 3 major aid points between the start and the finish. Personal crew assistance is not part of the published checkpoint data - check the official runner guide.
Training for this race?
TrailMath builds periodized trail training plans around your goal race.
One Strava connection reads your last 90 days and estimates your finish on this course. Free, no plan needed.