Run Rabbit Run 100 is the most spectator-friendly mountain 100-miler in the U.S. Held in Steamboat Springs, Colorado in mid-September. 100 miles, 21,000 ft of climb, two simultaneous race formats — the "Hare" race (12-hour cutoff for elite finishers, $100,000 prize purse) and the "Tortoise" race (36-hour cutoff for everyone else). Started by trail-running legends and run with a unique mix of professional polish and small-race warmth.
The course
Two-loop course around the Steamboat ski-resort area, climbing through aspen forests up to ridge-top exposed sections, with views into the Yampa Valley. Signature sections: Long Lake (mile 17), Fish Creek Falls (mile 32), Summit Lake (the high point, around 10,000 ft). The course is more runnable than Hardrock or Wasatch — fewer technical sections, more rolling jeep roads and single-track.
By the numbers
- Distance: 100 miles (loop)
- Vert gain: 21,000 ft
- Vert per mile: 210 ft/mi (mountain)
- High point: ~10,000 ft
- Cutoff (Hares): 12 hours
- Cutoff (Tortoises): 36 hours
- Date: Mid-September (Friday afternoon start for Hares; Tortoises Friday morning)
How to qualify and enter
Tortoise race: open registration with a 50-mile or 100K qualifier required. Fills in 2-4 weeks of registration opening.
Hares race: invitation-only for elite runners, with a 12-hour finish required. The $100K purse split among top finishers makes this the highest-paying mountain ultra in the world.
The Steamboat advantage
Run Rabbit Run is built for spectators. The two-loop format means crew can see runners 4–6 times. Aid stations are accessible by car or short hike. The town of Steamboat fully embraces the race — restaurants, hotels, and downtown shops are ultra-friendly that weekend. This makes Run Rabbit Run the right race to bring family who want to spectate without spending all day in the woods.
Gear strategy
- Vest: 8–12L. Salomon Adv Skin 12.
- Shoes: Hoka Speedgoat 6 — runnable course rewards cushion.
- Layers: long sleeve + beanie for the high points; can drop into the 30s.
- Headlamp: primary + spare. 8–12 hours of dark for most finishers.
The Run Rabbit Run experience
Most finishers describe Run Rabbit Run as the most fun 100-miler on the calendar. The unique two-format setup, the Steamboat town atmosphere, and the friendliness of both the volunteer corps and the race directors make it stand out. Not as iconic as Western States or Hardrock — but for a first 100, or a second after a tough debut, the right pick.
What these sessions assume you are measuring with
Every pace, zone and power figure here needs something recording it. These three cover running, long days and the bike.
Garmin Forerunner 965 AMOLED multisport with the training-load and threshold metrics most of these sessions assume you can see day to day.
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COROS APEX 2 Series GPS Watch Sapphire titanium and the longest battery in its class, which is the deciding feature once a day out runs past a few hours.
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Favero Assioma Uno Power Meter Pedal Single-sided pedal power, the cheapest honest entry into training with watts rather than estimating from heart rate.
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