Blue Sky Trail Marathon & Half Marathon

Welcome to the Blue Sky Trail Marathon & Half, Fort Collins's original and only trail marathon. Taking place on the trails between Horsetooth Mountain Park and the Devil's Backbone Open Space, the course takes you on a north-south tour of the easternmost hogbacks of Northern Colorado's mighty Front Range. The marathon boasts 3,500 feet of elevation gain/loss, while the half marathon checks in at 1,800 feet, and the route offers a little bit of something for everyone. It is designed to appeal to both veteran trail runners and those looking to experience their first trail racing adventure. The generous nine hour cut-off should ensure a successful day for everyone. The course is 100% dirt and 90% sweet Colorado singletrack. The terrain ranges in difficulty from smooth dirt trail to technical rock gardens. A small portion of the route is on smooth dirt road (no motor vehicle access) and gravel bike path, with the meat of the running done on the beautiful and distinctive redstone hardpack of the Blue Sky Trail. After the race, kick back and enjoy the always-popular barbecue and generous sponsor giveaways. Start : Blue Sky Trailhead , Horsetooth Mountain Park . Fort Collins, Colorado Distance : 26.7 miles (3,500') or 13.4 miles (1,800') Min/Max Elevation : 5,300'-6,500' Average Elevation : 5,700' Marathon Terrain : Marathon: 22mi dirt singletrack, 3mi rocky singletrack, 2mi dirt road; Half Marathon: 13.0mi dirt singletrack, 0.5mi dirt road Fauna : Deer, abert squirrel, golden eagle Registration Cap : 400 Marathon / 400 Half Time Allowance : 9 hours Marathon / 6 hours Half Marathon Dates : Marathon: Oct 17, 2026; Half Marathon: Oct 18, 2026 Registration Fees for the 2026 Blue Sky Marathon & Half Marathon are as follows: Marathon: Dec 15 – Feb 28: $110 + $7.60 fee March 1– June 30: $120 + $8.20 fee July 1 – Oct 17: $130 + $8.80 fee Packet Pickup: $145 Half Marathon: Dec 15 – Feb 28: $90 + $6.40 fee March 1– June 30: $1