Endure Trail Runs
About this race
The Human Potential Running Series Presents:
The Endure Trail Runs @ Mueller State Park
The Endure 12-Hour is a one-of-a-kind 12-Hour timed event designed by YOU… and tiny colorful balls. Each runner will pull colored balls from a bucket, which determines the loop they’ll next run. This continues for up to 12 hours; the runner’s result is the miles they ran within the allotted time. You are not required to run for all 12 hours, as your final result is the number of miles you ran within the time you participate!
The 10k, Half Marathon, and Marathon are great ways to enjoy Mueller State Park’s natural beauty in a supportive, “no-pressure” environment. All three distances feature a generous 11-hour cutoff.
All courses feature double-track and single-track trails with ZERO pavement, and an aid station you’ll want to hang around at for hours (we’re that much fun)!
Formerly Known As The Tommyknocker 12-Hour & Mine Shaft Half
Pick your distance
Running
10k
Runner's will complete the green then orange loops, for a slightly Heavy 10k Finish.
Trail running
Half Marathon
Runner's will complete the green loop, followed by the orange loop, followed by the purple loop for a half marathon distance.
Marathon
Runners will complete the green loop, the orange loop, the purple loop (including Grouse Mountain), and the blue loop, finishing with the red loop in that order for a full marathon distance. That is one of each loop associated with the event!
12-Hour (Tiny Balls)
Tiny Balls determine your fate. You'll pull a colored ball from a bucket before each loop. The color you pull is the loop you'll next run. Watch out for the black balls! Each runner will run their own unique individual sequence of loops. This is a timed event. You will run as many miles as you can or want within the 12-hour time limit. Want to run for 7 hours then go home? Totally fine! Results are tabulated by the total number of miles run, and not by time.
12-Hour (Endure- LRS)
Tiny Balls determine your fate. The RD pulls a colored ball from a bucket before each loop. The color he draws is the loop that the entire field will next run. A second ball (Pace Ball) is pulled to determine the slowest pace at which the loop must be completed. Pace ball times range from 14:00 to 16:30 minutes per mile. Fail to return in time to start the next loop, and you'll be eliminated. There are no black balls in this event. All runners will run the same sequence of loops. Your goal is to survive for 12 hours. Those who endure are finishers. Those who are eliminated will be allowed to switch to the other 12-hour event to continue running for the remainder of the event. See race website for more details.
Typical race-day weather
Based on 13 years of Open-Meteo archive data for this event's race dates in Divide, plus the 3 days either side.
The sun rises at 5:47 AM and sets at 8:06 PM local time (MDT) in Divide on May 15, 2027 — 14h 18m of daylight.
Course
No course map published yet.
The organizer hasn't released a route for this event, and we don't publish guesses. If you're the organizer, send us a GPX file and we'll draw the profile.
Reviews
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Results — Endure Trail Runs
Other races near Divide
Different organizers, within 40 miles, in the next three months
Manitou 5K
Ymca Creepy Crawl 5K
Fall Series and Community Cup Awards + Membership Dinner
The Palmer Lake .5K (Yes "Point" 5)
Where this page comes from. Race details were last updated on . We re-check listings regularly and again in the week before race day.
- Entries, prices, waves and inclusions — the event's official registration page
- Temperature and humidity — Copernicus ERA5 reanalysis via Open-Meteo (CC BY 4.0)
- Elevation and terrain relief — Copernicus DEM GLO-90, ESA (CC BY 4.0)
- Comparisons and counts — Race Discovery calendar, 1 Divide event
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