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Ultramarathon Database

Nathrop, Colorado · Trail

Official site

High Lonesome 100

A 100-mile loop through Colorado's Sawatch Range with 23,500 feet of climbing over five alpine passes, topping out at 13,150 feet.

2025·2026·2027

Friday, July 16, 2027

Distances

Distance
100 mi (161 km)
Vert gain
23,500 ft (7,200 m)
Cutoff
37 hr

WSER 2028 qualifier (sub-37:00)

Course records: Becca Bramley 21:55:49 (2026) · Jeffrey Colt 18:52:00 (2025)

About

The High Lonesome 100 runs a loop through the Sawatch Range near Mount Princeton, following the Continental Divide and Colorado Trails over five alpine passes and through two ghost towns. It climbs 23,500 feet and reaches a high point of 13,150 feet, with a 37-hour cutoff.

Founded in 2017 and run by the volunteer team at Freestone Endurance, it fills by a two-pool lottery and counts as a Western States 100 qualifier. The field is small, and the race leans on an experienced crew of aid station volunteers.

Course

A high-altitude loop on the Continental Divide and Colorado Trails, over five alpine passes with 23,500 feet of gain and a 13,150-foot high point. The start and finish sit at the base of Mount Princeton on County Road 321. The cutoff is 37 hours.

How to register

Entry is by lottery, drawn live each winter, with separate male and female pools and a waitlist. A qualifying trail race is required. The 2026 race is full.

Results by year

  • 2027July 16, 2027 · upcoming
  • 2026July 17, 2026 · completed
    Ryan Sullivan 19:56:30 · Becca Bramley 21:55:49 (CR)
  • 2025July 18, 2025 · completed
    Jeffrey Colt 18:52:00 (CR) · Rachel Entrekin 21:56:16 (CR)

Official links