Sunday, September 6, 2020 | 6am Start

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.


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Aid Stations & Cutoffs (We are 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 (No Cut Off)
  • Moonlight Lodge#2: 11.5 Miles (10:30 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 (New in 2019)
  • 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
  • Runners must check into and out of each aid station. Again this is for the safety of the runners and any potential rescuers!

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 10 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 trail congestion and promote safety along the course, the 50K will be started in 3 waves at 5-minute offsets. If you believe you will finish in the first third of the field we recommend you sign up for wave one. If you think you will be in the second third, please sign up for wave two, and so on for the 3rd. This allows for less congestion on the trail and better flow for all racers if you select the most appropriate wave for you.

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

Although they are part of the 50K course, please be aware that you may not run or hike on the Downhill Mtn. Biking Trails of Big Sky Resort as they are built specifically for downhill mountain biking and are used by downhill mtn bikers. Not only is it not allowed, it is not safe during lift operation hours when those trails receive a lot of use. We understand this makes it challenging to scout the course, but if you are to get out on the course we recommend getting into the terrain on the summit as well as some of the nice single track on the Moonlight Basin side of the resort, as well as some of the single track trails on Andesite mountain. Those are open to hikers and runners. Lastly, the course will not be marked until a day or two prior to the race, so finding your way around the course will be quite hard. Again, we recommend getting a general understanding of a flow for the course and the type of terrain you will encounter instead of dialing in the exact route.


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 will receive a 50% Refund.
  • Rut Runners may also move down in distance. This must be done no later than August 15th.
  • 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.