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The Rut Mountain Runs
50km5028km2821km2111km114.6km4.6

The Rut Mountain Runs 21k

21.0km·1220m+
September 10
Big Sky,
United States
source

Race Pace Calculator · GPX Analyzer · Trail Finder

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Full calendar: United States

The Rut Mountain Runs 21k · Race profile

Distance
21.0km
Gain
1220m+
Max
2967m
Min
2212m

About The Rut Mountain Runs 21k

The Rut Mountain Runs 21k is the 21.0km trail race at The Rut Mountain Runs 2027 (Big Sky, United States). The race starts on September 10, 2027. It starts and finishes in Big Sky.

Race strategy

Hold a steady pace and save energy for every section.

  • High point at 2967m. Control your HR at altitude.
  • 651m descent. Go easy, save your quads.
  • Control your HR on the first mountain, save your quads on the descents until 12.6km, then run your race pace.
  • Start · 0.0km–1.4km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
  • Settle in · 1.4km–5.5km · Climb of 650m. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace. At altitude your pace drops, and that's fine.
  • Work · 5.5km–18.3km · Climb of 150m, high point 2967m, descent of 651m averaging 12%. Plus 1 more climb and 2 descents. This is where the race is built: steady, solid effort. Climb by heart rate or breathing, not pace. This descent is hard on the legs: short steps, stay in control, poles if you have them. At altitude your pace drops, and that's fine.
  • Home · 18.3km–20.5km · Climb of 115m. Build to the finish: leave whatever you have left out on the course. Climb by heart rate or breathing, not pace.

Course

The course climbs 1220m+. With 58m/km of climbing, this is a true mountain course with sustained climbs and descents. By gradient, 44% of the distance is uphill, 47% downhill and 9% flat. The longest climb runs 5.5km at an average 11.8% grade (650m of vertical). The longest descent runs 5.5km at an average 11.9% grade (651m of vertical). The steepest climb averages 21.6% over 0.5km. The steepest descent drops at 23.8% over 0.6km.

Summits

The course also passes close to Andesite Mountain (2661m).

Poles

Trekking poles are worth taking: about 3.6km of the course favours them.

Quad damage

Quad damage risk is moderate (index 20 of 100), with 63% of the load in the first half: 1 descent deserves a plan and a couple of downhill sessions before race day.

  • Control your HR on the first mountain, save your quads on the descents until 12.6km, then run your race pace.
  • #1 · 7.2–12.6 km · 651 m D−, -11.9% · 7.9 km ahead → control
  • 14.7–18.3 km · 435 m D−, -12.1% · 2.2 km ahead → your pace

This page has a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for The Rut Mountain Runs 21k.

Other distances of The Rut Mountain Runs 2027The Rut Mountain Runs 50k (50.0km)·The Rut Mountain Runs 28k (28.0km)·The Rut Mountain Runs 11k (11.0km)·The Rut Mountain Runs Lone Peak Vertical Kilometer (4.6km)

Other editions of The Rut Mountain Runs 21k2026·2025

Official websiteruntherut.com