
Fort Collins, United States of America · Saturday 17 October 2026
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: $100 $7.00 fee July 1 – Oct 17: $110 $7.60 fee What You Get in Retur
Adjusted Time
1:40:47
Time difference: -4.2 minutes compared to a flat, road, temperate course.
Blue Sky Trail Marathon & Half Marathon is a half marathon held in Fort Collins, United States of America, scheduled for Saturday 17 October 2026. The course is run on road surface with 0m of total elevation gain, reaching a maximum altitude of 0m above sea level. For registration and full race details, visit the official Blue Sky Trail Marathon & Half Marathon website.
This is a very flat course with only 0m of total elevation gain across the full distance. The course ranges from 0m to 0m above sea level — a 0m elevation range that makes it one of the flatter races available. Runners targeting a personal best will appreciate the minimal climbing.
Blue Sky Trail Marathon & Half Marathon is run on road surfaces, which provide the fastest and most predictable conditions for marathon running. Road courses allow for consistent pacing and are typically the best choice for runners targeting a personal best time.
Our difficulty rating for Blue Sky Trail Marathon & Half Marathon is calculated using a model that combines elevation gain, temperature impact, and surface type. Use the difficulty calculator above to enter your target finish time and see exactly how many minutes this course would add or subtract compared to a perfectly flat, cool, road-based half marathon. Faster runners and slower runners are affected differently by the same course conditions, so the difficulty is personalised to your pace.
Looking for an easier marathon or a tougher challenge? You can also compare Blue Sky Trail Marathon & Half Marathon against other half marathons to find the right race for your goals.
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