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.