Sunday, September 17, 2023 | 6 AM START

In 2023 the Rut 28K, 50K, and VK will not access the Lone Peak summit due to tram construction. Do not despair, though, we have found a great course option that still gets you on the ridge ascent to Lone Peak and within spitting distance of the summit for all 3 events!

For the 28K & 50K, we will still go within a third of a mile and 700 vertical feet from the summit. Runners will then descend down a large scree slope and wrap around to the Dakota territory before connecting back into the original 28K and 50K courses. This section is only 2.3 miles in total. Overall course distances for 28K and 50K will be within a quarter mile distance and 600 vertical feet of gain of the original courses.

There are sections of this course, including the ascent and traverse of Headwaters ridge, as well as the ascent of Bone crusher ridge towards the summit of Lone Peak, which are extremely steep and technical with sections of exposure and rockfall hazard. The result of a fall in these sections could be injury or death.  The responsibility falls on the participant to have the skills to traverse these areas safely. Do not let the distance fool you. 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. If you are interested in the 50K but just don’t feel ready for the technical sections, we suggest checking out our new Rut 20K course.


OnX Backcountry 50K Map

2023 Summit Reroute Map

Aid Stations & Cutoffs (updated for 2023)

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)
  • Dakota (Water Only): 21.7 Miles (3:15 PM Cut off)
  • Moosetracks 24: (4:15 PM Cut off)
  • Andesite: 26.2 Miles (5:15 PM Cut off)
  • Finish Line: 30.7 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: 10,000 ft / 3,200 Meters
  • Elevation Loss: 10,000 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, 60-69, 70+)

We have doubled our cash purse in 2023 and will have $9000 in cash prizes for the top 3 overall men and women of the 50K!

  • First: $3000 (USD)
  • Second: $1000 (USD)
  • Third: $500 (USD)

Wave Starts

When participants sign up for the 2023 Rut they will share an estimated finishing time for their event. We will then assign waves based on their estimated finishing time and send an email out with wave assignments. There will be 5 waves separated by 5 minutes each for the 28K 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. 

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. Drop bages are to be dropped off in the base area between 5:15-5:45 on race morning.


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 2023 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 the 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.