Sunday, September 4, 2022

The Rut 50K is an extremely challenging mountain run held on Big Sky Resort property. Race participants will find themselves covering ALL types of terrain including jeep roads, forested single track trails, alpine ridge lines and even to the iconic summit of Lone Peak!

There are sections of this course, including the ascent and traverse of Headwaters ridge, as well as the ascent and descent of Lone Peak, which are EXTREMELY STEEP & TECHNICAL with sections of exposure and potential rockfall hazard. We will have safety personnel along these sections keeping an eye out for runners and assessing any objective hazards, but the responsibility falls on the race participant to be aware of your surroundings and other runners. This is a true mountain course so please treat it with the respect it deserves! We strongly encourage you to become familiar with the course terrain before registering for this event.

OnX Backcountry 50K Map

Aid Stations & Cutoffs (We are a cupless event!)

There are 5 fully stocked aid stations located along the 50K course. Each aid station will be supplied with water, Skratch Labs goodies, sweet and salty snacks, first aid, and energetic volunteers!

  • Moonlight Lodge#1: 5.6 Miles (8:15 AM Cut Off)
  • Moonlight Lodge#2: 11.5 Miles (10:00 AM Cut off)
  • Swiftcurrent: 18.7 Miles (1:00 PM Cut off)
  • Summit:19.9 Miles (2:30 PM Cut off)
  • Shedhorn Water Only station: Mile 22 (No Cut off)
  • Andesite: 26.5 Miles (5:00 PM Cut off)
  • Finish Line: 31 Miles (6:45 PM Cut off)
  • Cut-off times will be strictly enforced for the safety of the runners and the volunteers

By the Numbers

  • Distance: 31 Miles / 50K
  • Elevation Gain: 10,500 ft / 3,200 Meters
  • Elevation Loss: 10,500 ft / 3,200 Meters
  • 60% Single Track
  • 25% Dirt Road
  • 15% Off Trail

Due to the alpine and exposed nature of our 50K course, race organizers reserve the right to change the course in order to limit risk to rut runners.  Here is a description of our 50K plan B course. It is a few miles shorter, has near 7,000 ft elevation gain, and does not access the Headwaters Ridge, or Lone Peak Summit.

September in Montana often brings the first winter snowstorms and blizzards to the high peaks.  Or, a long Indian summer extending into September can also mean major electrical storms in alpine environments.  The Rut 50km course (as planned) is on a high peak (11,160 feet), and on extremely exposed alpine terrain.

In the event that a major snowstorm or dangerous electrical storm hit Lone Peak on race day, the race directors reserve the right to alter the 50km course to keep runners safe.  The Headwaters Ridge and Lone Peak sections of the original course are simply too exposed and technical to be safe for runners or safety personnel in the event of a major storm on race day.  The “Plan B” course would remain approximately 50% true to the original course.  The change would be that the course would stay off the high exposed ridgelines and not go to the summit of Lone Peak.

Plan B Course Description: 

Though we haven’t GPS’d the thing, you can expect it to be a few miles shorter than 50K, and also have  around 7,000 ft elevation gain. Giver or take a bit.

The first 12.1 miles of the alternative course would remain the same as the original course (Soul Hole-Tango-Challenger service road-Moonlight-Ullery’s Lake loop-Madison Connector-Madison Village-Moonlight Loop trail-Elkhorn trail).

Once reaching the top of the Elkhorn trail, where you intersect with the service road, head left and down the road.  This road will connect back onto the Challenger service road. Head right following Fast Lane downhill and underneath the Challenger ski lift line back onto Big Sky Resort property.Go until the junction of Fast Lane and the Cairn’s Way single track mountain bike trail.Take a right at the junction onto the Cairns Way trail. Head uphill on Cairns Way trail until you connect onto the North Access dirt road.Continue uphill on this road until the junction with the Morning Star dirt road.Take a right onto Morning Star and continue uphill to the base of the Lone Peak tram and the Tram Dock Aid Station. Head back downhill along the Morning Star dirt road to the junction of Morning Star and the North Access double track.At the junction, turn right and head uphill on the North Access road. 

Continue up the North Access road past the Swiftcurrent lift, heading south. You will now be running on the Duck Walk service road, heading south towards the top of Shedhorn ski lift.  Once at the top of Shedhorn, you will do a steep off-trail descent through a rocky boulder field through Rockville Bowl, then hang a sharp right (again, off trail section – follow course  markings!) and head back up a short steep climb (up the “screaming left” ski run).This will take you through rocky terrain to the top of the Dakota lift. Once you reach the top of Dakota, descend the Dakota road to the bottom of Dakota lift.  You are now back on the original race course for the remainder of the race (see 50km detailed course description).

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We will have unique handmade awards for top three in each age group. (16-19, 20-29,30-39, 40-49, 50-59, 60+)

Oh yeah, we also have a $4500 prize purse for the top 5 overall Men and Women in the 50K!

  • First: $1000 (USD)
  • Second: $500 (USD)
  • Third: $350 (USD)
  • Fourth: $250 (USD)
  • Fifth: $150 (USD)

Wave Starts

To limit congestion at the start line, we will have three waves of 5-minute rolling start windows for our 50K this year. (A rolling start means that you can begin anytime within the 5-minute window of each wave.)
We did not offer wave options when you registered for the Rut, therefore, you must self-select and join the appropriate wave on race day.
If you hope to be in the first third of finishers, please join Wave 1, in the second third of finishers, Wave 2, and the last third, Wave 3. Self-selecting appropriately reduces unnecessary passing on the trail.
Lastly, overall awards and prize money will be based on the time from when the gun goes off with the first wave. Age group awards will be based on chip timing.

Drop Bags

Runners will be able to have one drop bag on the course, which will be at Swiftcurrent Aid Station (Mile 18.7)

To be more organized in transporting our drop bags and having them ready for you each 50K participant will receive a drop bag to use at packet pick up. The drop bag will have a place to write your bib number. If you can’t fit something into the provided drop bag then you don’t need it.  Thanks for your understanding.


The 50K starts at 6am which will be in the dark this year for the first 30-45 minutes of the race. Although, we do not have drop bags at our first Aid Station (Moonlight Lodge – Mile 5.6) We will have a volunteer collecting headlamps from runners should you choose to leave yours there. The headlamps will then be transported back to the 50K start and finish area and you may pick them up in the same location where you can retrieve your 50K returned drop bags. For this to work, you must have your name or bib number on your headlamp to retrieve it! We are working hard to offer this as a service to you so you do not have to carry any extra weight around the course, however, we are not responsible for any lost of broken headlamps. You are leaving them with us at your own risk!


Due to the nature of our course and the fact that this is just a little ‘ol 50K, there will be no crewing of runners allowed. You are, however, highly encouraged to get out on the course and see your runners as much as possible and cheer for them!

Dropping out:

You must inform the nearest aid station captain if you drop out of the race.

Course Markings

This is not an orienteering race. The race organizers will do everything they can to have the course marked well for race participants the day of the event. Runners must follow trail marking and not cut switchbacks. Off-trail sections of the course will be marked in a way that race participants should be able to see from each course marking to the next to help guide them along the course. The Rut 50K will be marked with yellow tape and pin flags with a black Rut Logo on them.

Course Reconnaissance

We welcome you to check out the Rut course prior to the event, but please be aware that you cannot go on the downhill mountain biking trails other than race day. IT is unsafe to do so. Also, in 2022 the Bonecrusher ridge climb to the summit will be closed due to tram construction.  Please check out Big Sky Resorts summer trails map to see what trails are running and hiking are allowed before heading up to the resort.


Please be prepared for any type of weather. Though weather in Big Sky is relatively mild and stable in mid-September historically, we are still in the mountains and conditions can quickly change. This is a challenging run on challenging terrain and the race organizers reserve the right to stop the race at any time, should they deem the course unsafe due to weather. The race organizers will have a 50K Plan B course, which will not take race participants into exposed alpine terrain, should extreme weather exist on race day.


50K Fine Print

  • Pacers and dogs: Not allowed .
  • Trekking poles: Allowed
  • Headphones: highly discouraged due to areas with rockfall hazards and potential wildlife hazards along the trail.
  • Crewing: Not allowed
  • Speakers: Out of respect of others, please do not use speakers for music that other people can hear. Not everyone loves your music.
  • Course Changes: Due to the mountainous and technical nature of this course, race organizers may choose to make course changes on race day due to severe weather with the race participants safety in mind.

Rut Registration Policy

  • There will be no deferrals, credits, transfers, or waitlists for any Rut race.
  • Rut Runners who must drop out due to unforeseen circumstances may do so by May 15th and will receive a 50% refund.
  • Rut Runners may also move down in distance. This must be done no later than August 1st.
  • The 50K can move to the 28K or 11K, but not the VK.  The 28K can move to the 11K, but not the VK.  The VK can move to the 11K. A transfer in distance will be charged a $5 processing fee.
  • Questions? Check out our Rut Registration FAQ's page.