Blue Sky Trail Marathon
Blue Sky Trail Marathon covers 26.7 miles of Fort Collins singletrack, red-rock hogbacks, and dirt road with roughly 3,500 feet of climbing.
Quick facts
- 26.7-mile trail marathon with about 3,500 feet of gain.
- Mostly singletrack between Horsetooth and Devil's Backbone.
- Nine-hour limit with several intermediate cutoffs.
About the Blue Sky Trail Marathon
Gnar Runners' Blue Sky Marathon connects Horsetooth Mountain Park and Devil's Backbone Open Space. It is designed for experienced trail runners and road runners moving into longer trail racing.
Course
About 90 percent of the route is dirt singletrack, ranging from smooth hardpack to rocky technical sections. The 26.7-mile course gains about 3,500 feet and uses an out-and-back extension toward Devil's Backbone.
Race-day weather
Fort Collins can be crisp and dry in mid-October, but exposed ridges bring sun and wind while shaded trail sections stay cold. Early snow is possible.
Past Blue Sky Trail Marathon dates and results
| Year | Date | Status | Results |
|---|---|---|---|
| 2026 | Saturday, October 17, 2026 | Results available | Open results |
| 2025 | Saturday, October 18, 2025 | Results available | Open results |
| 2024 | — | Results available | Open results |
Your race experience
Ran the 2026 Blue Sky Trail Marathon?
Share what helped you on race day: the course, transport, aid stations or finish area.
Blue Sky Trail Marathon FAQ
When is the Blue Sky Trail Marathon?
We're waiting for the finalized date for the 2027 Blue Sky Trail Marathon. The most recent running was on Saturday, October 17, 2026.
Featured collections
Found an official update?Send race details or links
Send us confirmed dates, registration links, results, live tracking, or course changes. Include the source link so runners can reach the right information.