Fort Collins’ original trail marathon adventure - run epic Front Range singletrack from Horsetooth to Devil’s Backbone, then celebrate with post-race BBQ and giveaways.
Blue Sky Trail Marathon takes place on October 17, 2026 in Fort Collins, CO.
Blue Sky Trail Marathon is 26.7 miles with 8,890 ft of elevation gain.
No — Blue Sky Trail Marathon uses open registration; no lottery is required.
Yes, crew is allowed at Blue Sky Trail Marathon. Sign in to Trailrace to see crew access for each aid station.
No, pacers are not allowed at Blue Sky Trail Marathon.
Yes, Blue Sky Trail Marathon allows drop bags.
Blue Sky Trail Marathon has 6 aid stations along the course.
The overall cutoff for Blue Sky Trail Marathon is 9h. Per-aid-station cutoffs are available to signed-in Trailrace members.
Other trail races within 46 miles
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.
Suitable for first-timers
Fort Collins, CO, United StatesOctober 17, 2026
Well-maintained, non-technical trails
| Location | Mile | Elevation |
|---|---|---|
Start Start | 0.0 | 5,528 ft |
Towers Aid Station | 4.0 | 6,476 ft |
Blue Sky Aid Station | 9.1 | 5,486 ft |
Indian Summer North Outbound Aid Station | 13.1 | 5,482 ft |
Indian Summer South Outbound Aid Station | 15.3 | 5,482 ft |
Hunter Turnaround Checkpoint | 17.8 | 5,463 ft |
Indian Summer South Inbound Aid Station | 20.4 | 5,482 ft |
Indian Summer North Inbound Aid Station | 22.7 | 5,482 ft |
Finish Finish | 26.7 | 5,499 ft |
Sign in to see cutoffs, crew access, drop bags, and services for every aid station.
No dogs allowed on course
No crew rules specified
The race is held mid-October in Fort Collins, Colorado at 5,300–6,500 ft elevation along the Front Range foothills. Expect cool-to-cold mornings at the 7am start, typically in the low-to-mid 30s°F (1–4°C), warming to the high 40s–60s°F (9–16°C) by afternoon. October is shoulder season on the Front Range — sunny days are common but cold fronts can bring rapid temperature drops, wind, and occasionally early-season snow. The exposed hogback ridgelines in the Devil's Backbone section of the course amplify wind chill. Layers and weather-adaptable gear are advisable even in good-forecast conditions.
No required gear specified
No recommended gear specified
No reviews for this event yet. Be the first to share your experience!
