Logo

Blue Sky Trail Marathon

Fort Collins, United States • 18-19 Oct 2025

The Blue Sky Trail Marathon and Half Marathon are scheduled for October 18-19, 2025, in Fort Collins, Colorado. The event features a scenic course through trails between Horsetooth Mountain Park and the Devil’s Backbone Open Space, offering a mix of dirt singletrack, rocky terrain, and gravel paths. The marathon covers approximately 26.7 miles with 3,500 feet of elevation change, while the half marathon is about 13.4 miles with 1,800 feet of elevation. Designed for both seasoned trail runners and beginners, the race emphasizes a challenging yet accessible experience, with generous cut-offs, aid stations, and post-race festivities including food and sponsor giveaways. Visit the organization's website for the most recent information.

United States Colorado Fort Collins

Race information

Website Registration
26 mi
3500 m+
Blue Sky Trail Marathon
13 mi
1800 m+
Blue Sky Trail Half Marathon
Visit the organization's website for the most recent information.
Trail runs nearby

Samson's Revenge

Estes Park - 27 mi from Fort Collins

Samson's Revenge is a trail running event held at the YMCA of the Rockies in Estes Park, Colorado, honoring Samson, the famous elk of the Rockies. The race offers three distances: 10K, 27K, and 55K, featuring fast single-track trails with significant elevation gain, including a challenging ascent of..

Weld Your Mettle Running Festival

Eaton - 20 mi from Fort Collins

...

The Weld Your Mettle Running Festival is a four-day event taking place in Eaton, Colorado, from May 23 to May 26, 2025. It offers a variety of running challenges suitable for all levels, including a 7K run, ruck, and timed events ranging from 3 to 48 hours, either solo or as part of a relay team. Pa..

Crazy Legs Trail Run

Loveland - 14 mi from Fort Collins

The Crazy Legs 10k+ Trail Run takes place at Devil’s Backbone Open Space in Loveland, Colorado. The course features a scenic loop through Hidden Valley, Hunter Loop, Laughing Horse Loop, and Wild Loop trails, covering over 10 kilometers with minimal overlap to prevent congestion. Marked by flour arr..

Estes Park's Backyard Ultra

Estes Park - 27 mi from Fort Collins

The Estes Park Backyard Ultra is an endurance running event held along the scenic Lake Estes, supporting Childcare and Family Services. Participants run a 4.252-mile course on a paved bike trail, completing a lap every hour until only one runner remains. The race features no predetermined end time,..

Timberview Trail Run

Bellvue - 5 mi from Fort Collins

The Timberview Trail Run is a scenic trail racing event held at Lory State Park in Colorado, featuring three distances: 5K, 5 miles, and 10 miles. The race offers a beautiful course among treetops with views of Horsetooth Reservoir and the surrounding foothills. The 5K is beginner-friendly, while th..

Lory Summer Trail Series

Bellvue - 5 mi from Fort Collins

The Lory Summer Trail Series is a fun, low-key trail running event held each Tuesday evening in August at Lory State Park, Fort Collins, Colorado. It features a series of shorter races with distances ranging from 5K to 12K, designed to welcome new trail runners and help experienced racers sharpen th..