Ultramarathon

High Lonesome 100

High Lonesome 100 loops through Colorado’s Sawatch Range with five alpine passes, 23,300 feet of climbing, and a 37-hour cutoff at high altitude.

Next raceFriday, July 16, 2027
Distance categoryUltramarathon
LocationNathrop, Colorado
Get alertsLast checked August 4, 2026

Quick facts

  • Five alpine passes, with a high point near 13,100 feet.
  • About 66% singletrack and 27% mining roads on the current course breakdown.
  • Lottery entry requires a qualifying trail-race finish and completed trail work.
  • Qualifier policy excludes timed events, backyard races, and UTMB-owned events.

About the High Lonesome 100

High Lonesome 100 keeps the field small and the entry bar high. A lottery, required trail qualifier, and trail-work requirement lead into a remote Sawatch Range loop built around mountain competence, not just endurance.

Course

The 100-mile loop gains about 23,300 feet and averages 10,426 feet above sea level. Five alpine passes, two ghost towns, and long sections of the Continental Divide and Colorado Trails sit inside a 37-hour limit.

Race-day weather

Mid-July in the Sawatch Range can bring strong sun, wind, hail, and fast afternoon storms. The high average elevation magnifies temperature swings, and the overnight miles can turn cold after a warm day.

Past High Lonesome 100 dates and results

YearDateStatusResults
2027Friday, July 16, 2027Upcoming
2026Friday, July 17, 2026CompletedOpen results
2025Friday, July 18, 2025CompletedOpen results
2024Friday, July 19, 2024CompletedOpen results

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High Lonesome 100 FAQ

When is the High Lonesome 100?

The 2027 High Lonesome 100 is on Friday, July 16, 2027.

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