Blue Sky Marathon

October 18, 2026

Start Time : 7:00 a.m.
Number of Places : 400

The Blue Sky Marathon is a trail race, hosted by Gnar Runners, through Horsetooth Mountain Park in Colorado. There is also a Blue Sky Half Marathon.

Blue Sky Marathon Route
Runners follow a rugged (22mi dirt singletrack, 3mi rocky singletrack, 2mi dirt road) out-and-back course, starting and finishing at the Blue Sky Trailhead. Using the trails between Horsetooth Mountain Park and the Devil's Backbone Open Space, the Blue Sky course is a north-south tour of the easternmost hogbacks of Northern Colorado's Front Range mountains.

Blue Sky Marathon Entry
* Entry Fee : $128.20 (until Jun 30), $138.80 (until Oct 16)
* Registration Deadline : October 16

Contact Details
Contact : Nick Clark & Brad Bishop
Email : racedirector@gnarrunners.com
Website : https://gnarrunners.com/blue-sky-marathon/

Further Information
* Cut-off Time : Runners will be expected to finish within 9 hours.