The Rut Mountain Runs

The distances

The Rut began in 2013 with a 50K and a 12K. The Vertical Kilometer followed in 2014, the 28K in 2015, and the 21K in 2023 to bridge the gap between the 11K and the 28K.¹ The race describes itself as one of the largest trail running events in North America, with roughly 4,500 registered runners in 2025.¹

The 50K is 31 miles with 10,500 feet of vertical gain and loss, and the 28K is 17.6 miles with 7,800 feet.² The 21K is 13.4 miles with 4,000 feet, and the 11K is 6.8 miles with 1,700 feet.²

The Lone Peak Vertical Kilometer climbs 3,623 feet in 2.85 miles.² The Trifecta combines the VK, 28K and 50K for 52.5 miles and 21,500 feet.² Trifecta runners are scored in each race and for overall Trifecta awards.¹⁴

How technical is it?

Very, on the longer courses. The 50K page warns of sections that are extremely steep and technical, with exposure and rockfall hazard, and says a fall there could result in injury or death.⁴ The 28K carries a similar caution: do not let the distance fool you, because it is a true mountain course.⁵

The VK starts at the Big Sky Resort base area at 7,534 feet and finishes on the summit of Lone Peak at 11,166 feet, and it is all uphill.³ The second half, along Bone Crusher and Alto Ridge, is described as extremely steep and technical.³ Finishers ride the Lone Peak Tram and Explorer Gondola back down.³

The 21K is the option for runners who want mountain terrain without the ridgelines. It does not traverse the exposed and rugged ridgelines of Lone Peak the way the 28K and 50K do.⁶ The 11K is a loop on lower and mid-mountain single-track.⁷

The Rut is sanctioned by the World Mountain Running Association.¹³

Cutoffs and aid stations

Aid station cutoff times are strictly enforced and are the same whichever wave you start in.⁴ A runner who misses a cutoff cannot continue, and anyone who carries on against the aid station captain's request is disqualified.⁸

The VK has a one-hour cutoff at the top of the Swiftcurrent chair and an overall course cutoff of 2.5 hours.³

In 2026 the 50K had five fully stocked aid stations and one that carried only Skratch products.⁴ The 28K had three fully stocked stations plus one Skratch-only station, and the 21K had three.⁵⁶ 50K runners receive a drop bag at check-in for the Swiftcurrent aid station.⁴

Mandatory gear

Runners in the 28K and 50K have to show their mandatory gear, along with photo ID, to pick up a bib.¹² Without the required gear you cannot run.⁹

The list includes a hooded jacket that is waterproof and breathable, not just water resistant, and between 16 and 32 ounces of water-carrying capacity depending on the race.⁹ All 50K runners must carry a headlamp, because the 50K starts before sunrise.⁹

VK runners are required to carry a waterproof jacket and a space blanket if the weather is cold or wet on race day.⁹ The equipment page notes that in 2024 the summit of Lone Peak had snow, wind and below-freezing temperatures.⁹

Rules

• Pacers are not allowed in any Rut race.⁸
• Crewing is not allowed. Aid comes only from volunteers at the aid stations.⁸
• Headphones are highly discouraged. If you wear them, use one earbud or bone-conduction headphones.⁸
• Not stopping to help a runner in need results in disqualification.⁸
• The minimum age for the VK, 28K and 50K is 16.¹⁰
• Overall awards are based on gun time, and you must start in Wave 1 to be eligible.⁸

Registration, caps and deferrals

Registration for the 2027 Rut opens on January 12 at 8 a.m. Mountain Time.¹⁰ Each distance has a cap, listed in 2026 as 825 for the 50K, 900 each for the 28K and 21K, 1,200 for the 11K, 375 for the VK and 100 for the Trifecta.¹⁰

There is no waitlist. Once an event fills, no more runners are admitted even if registered runners cancel.¹¹

Refunds are not offered under any circumstances.⁸ Runners who cancel by June 1 receive a 60% credit toward the following year's Rut, and those who cancel by August 1 receive 40%.⁴ Credits can only be used the following year.⁴

Entries cannot be transferred to another person.⁴ Switching to a different distance is allowed until August 15.⁴

The organizers can alter or cancel the event for extreme weather or wildfire smoke, generally an air quality index above 200 for extended periods.⁸

Schedule and dates

The official site says the 2027 Rut will be held September 9 to 12, while the registration listing gives September 10 to 12.¹⁰¹⁶ The 2027 race-day schedule had not been posted when these sources were checked.

In 2026 the VK was a mass start at 9:00 a.m. on Friday, the 28K went off in waves from 7:20 a.m. on Saturday, and the 50K started in six waves from 6:00 a.m. on Sunday.¹² Packet pickup for all distances was in Vista Hall of The Exchange in the Big Sky Resort base area.¹²

Travel and lodging

The nearest airport is Bozeman (BZN), a 45-minute drive from Big Sky on US Highway 191.¹⁵ Big Sky Resort's Huntley Lodge is a 30-second walk from the start and finish line, and entrants get discounted room rates at the resort.¹⁵¹⁰

Big Sky Resort does not allow camping on its property.¹⁵

Prize money

The 50K pays $3,000, $1,000 and $500 to the top three.⁴ The VK pays $1,000, $500 and $250.³ There is no prize money for the 21K, the 11K or the kids' Runt Run.¹³

The Runt Run is free, though children still have to be registered so a waiver is signed.¹⁷