Race Rules

We hope for close-to-normal conditions on race day, as related to the COVID-19 pandemic. Current race information reflects a normal year.  Details may change as race day approaches, and any changes will be communicated to registered runners well in advance.  For reference, here are the 2020 COVID Safety Protocols.

Race rules are designed to provide a safe and fair experience for everyone involved and to help ensure our ability to produce the race again next year.

Major rule infractions by racers will result in immediate disqualification of the racer. Please do not argue with or harass our volunteers but feel free to direct any questions and feedback to racedirector@gnarrunners.com.

Course Cut-Offs

The 50 mile race will be limited to 14 hours and will end at 7:30pm.
The 25 mile race will be limited to 12.5 hours and will end at 7:30pm.

Course cut-offs will be enforced at the following aid stations:

  • Soldier Canyon (Mile 24.9) at 12:15pm. 6:45 Total time (50mi).
  • Arthur’s Trailhead (Mile 32.3) at 2:10pm. 8:40 Total time (50mi) / 7:10 Total time (25mi).
  • Horsetooth Trailhead (Mile 39.5) at 4:35pm. 11:05 Total time (50mi) / 9:35 Total time (25mi).

This is a challenging course so some runners may find it difficult to meet these cut-off times. Any 50 mile runner who drops out or fails to meet the course cut-offs after completing the first 25 mile loop will be given a finish time in the 25 mile race, but will not be eligible for 25 mile overall and age group awards.

Note: Course cut-offs should not be used for pacing targets to reach the finish in 14 hours. We have set these cut-offs to give runners the maximum time on the course. To finish under the cut-off, runners should aim to hit the 25-mile turn around before noon, Arthur’s before 2pm, and Horsetooth before 4:30pm.

Bib Numbers and Check in

  • Bibs should be worn on the front and be visible at all times.
  • At each aid station (except the first time through Towers mile 7.1), volunteers will record runner bib numbers. Runners are responsible for making sure that aid station volunteers record their number. Please make sure that your bib number is visible from the front and call out and confirm your number when passing through an aid station. This is important so that we can keep track of runners and know that you are not lost or injured.

Dropping Out

  • If you need to drop out of the race for any reason, you must check out with the nearest aid station or course volunteer. If you do not inform us that you have dropped, we will assume that you are lost on the course. You will be held responsible for any Search and Rescue fees incurred.


  • There will be no water cups at the aid stations. Bottles can be filled at aid stations. Bottles or other supplies may not be stashed along the course. All runners should have the capacity to carry a minimum of 20 oz of water, whether in a bottle or a hydration pack. Dixie cups may be available at aid stations for carbonated beverages, but they cannot be carried out of the aid station.


  • Purposeful littering is prohibited and will result in an immediate disqualification. Carry garbage to aid stations and dispose of trash in proper garbage containers or hand garbage off to a volunteer. We recommend that you carry an extra baggie to stash small wrappers and gel tabs that can easily be dropped by accident.

Stay on the Trail

  • No bushwhacking or short cutting. Do not leave the trail when passing other runners. In case we have wet trail conditions, please run through any muddy sections to avoid widening the trail. (This is a trail race, leave the clean road shoes at home!)

Yield to Pedestrians and Horses

  • The trail system will be open to the public during the race. Pedestrians and Horses always have the right of way. Please be courteous and respect other users on the trail system. When approaching horses, talk to the rider and always wait until they give you permission to pass. Most riders will move their horses off the trail for you. Always try to assume higher ground when crossing paths with horses.
  • Mountain bikers are required to yield to runners but for your own safety, please use common sense and watch for blind corners and be careful when passing bikers.

Yield to Faster Runners

  • There will be some two way traffic as the 50 mile runners reverse direction on their second loop. Please yield to the faster oncoming runners. If being caught from behind, step aside where possible to allow the runner to pass.


  • Pacers are not allowed on the course and will result in the immediate disqualification of the runner.


  • Runners may not receive any additional crew aid outside of designated aid stations. Crewing on the course will result in the immediate disqualification of the runner.
  • Crew access is available at the Arthur’s Rock aid station, Horsetooth aid station, and the Soldier Canyon finish area (for 50 milers). Crews are welcome to assist aid station volunteers to help their runner.
  • Parking may be limited at the Horsetooth trailhead and crew access is not guaranteed. Runners should not rely on crew for any critical supplies and should plan to send these items in a drop bag.

Trekking Poles

  • This is a running race on tight – sometimes heavily populated – trails. No mechanical aid (poles, traction devices, etc.) unless approved by race staff prior to the race for a specific reason.

Drop Bags

  • Drop bags may be sent to the Horsetooth aid station (mile 10.3 and 39.5). Horsetooth Drop bags must be dropped off by 5am before the start of the 50 mile race. 25 Mile runners may hand off their Horsetooth drop bag at packet pickup.
  • Runners may also leave a drop or finish line bag at the Soldier Canyon start/finish area (Mile 24.9 for 50 Milers). Finish drop bags may be dropped off any time before the start of each race.
  • Please limit your drop bags to the size of a small duffel bag, day pack, or stuff sack.
  • Drop bags should be clearly labeled with your name and bib number and should be securely packed be outside in any weather for the duration of the race.
  • No glass, hard containers or coolers, or paper bags/boxes.
  • We will not be responsible for any lost or stolen items so please do not leave any valuables in your drop bags.


  • Dogs are not allowed on the course with runners. Dogs on leash are welcome at the park trailheads.


  • Park restrooms are available at the Soldier Canyon, Arthur’s, and Horsetooth trailheads. Additional portable toilets will be available for race participants at the Soldier Canyon start/finish.


  • Please do not leave any valuables at the start/finish or aid stations. Volunteers are not responsible for returning items left behind at aid stations. We are not responsible for any lost or stolen items.

Cancellation & Refund Policy

With the exception of wait list transfers, entries are non-refundable and non-transferable. In the event the race is cancelled due to extreme weather, fire, or for some other unforeseeable event, we cannot offer refunds or credits. See our registration page for our wait list transfer policy.