Ultramarathon Guide

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 17, 2026
Distance categoryUltramarathon
LocationNathrop, Colorado

Marathon Scout prioritizes official race websites, registration pages, timing providers, results pages, and race-linked live tracking. Last updated July 17, 2026.

High Lonesome 100 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.
Race-day forecast

High Lonesome 100 Race-Day Forecast

Race-day forecast data is unavailable right now. The weather notes below still cover typical race-day conditions.

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.

High Lonesome 100 course description

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.

Weather for the High Lonesome 100

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
2026Friday, July 17, 2026CompletedOpen results
2025Friday, July 18, 2025CompletedOpen results
2024Friday, July 19, 2024CompletedOpen results

High Lonesome 100 FAQ

When is the High Lonesome 100?

The 2026 High Lonesome 100 is on Friday, July 17, 2026.

How do I register for the High Lonesome 100?

You can register for the High Lonesome 100 at highlonesome100.com.

Does the High Lonesome 100 have live tracking?

Yes. Live tracking is available at opensplittime.org.

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