Sunday, September 15, 2023

Mandatory gear required for all 50K & 28K Rut Runners. Learn more HERE

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 (Cutoffs updated and moved back 15 minutes in 2022 to reflect later wave starts)

There are 5 fully stocked & 1 water-only aid station located along the 50K course. Each fully stocked 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: 10.6 Miles (9:40 AM Cut off)
  • Swiftcurrent: 18.7 Miles (1:15 PM Cut off)
  • Summit:19.9 Miles (2:45 PM Cut off)
  • Shedhorn Water Only station: Mile 22 (No Cut off)
  • Andesite: 26.5 Miles (5:15 PM Cut off)
  • Finish Line: 31 Miles (7:00 PM Cut off)
  • Cut-off times will be strictly enforced for the safety of the runners and the volunteers
  • Reminder: We are a cupless event!

Skratch Labs products you can expect on course in the rut 50K:

Anytime Energy Bars:
  1. Peanut Butter + Chocolate Chip (new flavor!)
  2. Cherries & Pistachios
Sport Crispy Rice Cakes
  1. Chocolate and Mallow
  2. Strawberry and Mallow
Sport Energy Chews
  1. Raspberry
  2. Blueberry (caffeinated) (new flavor!)
Sport Hydration Mix
  1. Lemon & Lime
  2. Raspberry limeade (caffeinated) (new flavor!)


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).

The Rut would not be possible without the support of our sponsors.


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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, 60-69, 70+)

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

When participants signed up for the 2022 Rut they shared an estimated finishing time for their event. We then assigned waves based on their estimated finishing time and have sent an email out with wave assignments. There will be 6 waves separated by 5 minutes each for the 50K in 2022.  Runners’ waves will be on the back of their bib and runners must start in their assigned wave.  Help us in limiting congestion on the trails. Thank you!

Lastly, overall awards 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.

50K Course Markings (Orange Pin Flags & Tape)

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 orange 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 allow running and hiking 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 September, 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 Rut Rules

  • Learn more about all Rut Rules HERE

Rut Registration Policy

  • There will be no deferrals, credits, transfers to other runners, or waitlists for any Rut race. No exceptions.
  • Rut Runners who must drop out due to unforeseen circumstances may do so by June 1st and will receive a 50% refund.
  • Rut Runners in some races may also move down in distance. This must be done no later than August 15th.
  • For example, the 50K can move to the 28K, 20K, or 11K, but not the VK.  The 28K can move to the 20K, or 11K, but not the 50K or VK. The 20K can move to the 11K, but not the 50K, 28K, or VK. The VK can move to the 11K only. The 11K cannot transfer to another event. A transfer in distance will be charged a $5 processing fee.
  • Questions? Check out our Rut Registration FAQ's page.