Blue Sky Trail Marathon
Fort Collins, United States • 17-18 Oct 2026
Blue Sky Trail Marathon and Half
The Blue Sky events are trail races held around Horsetooth Mountain Park and the Devil's Backbone Open Space near Fort Collins, Colorado. Courses run roughly north to south along the easternmost hogbacks of the Front Range and include varied singletrack and some dirt road.
Distances include:
- 26.7 miles, approximately 3,500 ft total elevation gain
- 13.4 miles, approximately 1,800 ft total elevation gain
Course details: the route is 100% dirt and about 90% singletrack. Terrain ranges from smooth dirt trail to technical rock gardens on redstone hardpack. Minimum and maximum elevations are about 5,300 ft to 6,500 ft; average marathon elevation is about 5,700 ft. The marathon route breakdown lists 22 miles of dirt singletrack, 3 miles of rocky singletrack, and 2 miles of dirt road. The half course lists about 13.0 miles of dirt singletrack and 0.5 miles of dirt road.
Support and logistics: field aid stations are fully stocked with sports drink, gels, water, soda, snacks and fruit; gluten free and vegan alternatives are available by request. Drop bags are permitted at designated start/finish locations. Registration is capped at 400 entries per distance and time allowances are 9 hours for the marathon and 6 hours for the half. Event rules require a minimum personal water carry and prohibit dogs and pacers. Visit the organization's website for the most recent information.