High Lonesome 100
Mount Princeton, United States • 17-18 Jul 2026
Event overview
The High Lonesome 100 is a 100-mile mountain ultramarathon held in Chaffee County, Colorado. The 2026 race dates are July 17-18, 2026. The event is organized by Freestone Endurance and is fully permitted on San Isabel and Gunnison National Forests and Colorado State Lands. The race has a 37-hour cutoff. The organizer partners with the Trail Mix Fund to waive registration fees for applicants who meet that program's criteria; this partnership began in 2024. The lottery application window runs from December 29 to January 4, with a drawing on January 9.
Course details
The race is a single large loop that starts and finishes at County Road 321, Mount Princeton (coordinates: 38.740213, -106.160962). The course distance is 100 miles with total elevation gain of about 23,300' and an average elevation near 10,426'. The high point is about 13,100' and the low point about 8,200'. The route crosses five alpine passes, includes roughly 27 miles on the Continental Divide Trail and 35 miles on the Colorado Trail, and passes through two historic ghost towns. Surface types are approximately 66% single track, 27% mining roads, 3% gravel roads, and 4% paved roads. About 15% of the course lies above treeline. Detailed maps, GPX/KMZ files, and downloadable turn-by-turn directions are provided by the organizer. Visit the organization's website for the most recent information.