The Blue Sky Marathon takes place on the trails between Horsetooth Mountain Park and the Devil's Backbone Open Space. 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.

Name Date and Time
Blue Sky Marathon 2022 (Blue Sky) Saturday, October 15, 2022 7:00AM (MDT) 262 entrants
Blue Sky Marathon 2021 (Blue Sky) Saturday, October 16, 2021 7:05AM (MDT) 255 entrants
Blue Sky Marathon 2020 (Blue Sky) Saturday, November 14, 2020 7:00AM (MST) 168 entrants
Blue Sky Marathon 2019 (Blue Sky) Saturday, October 19, 2019 7:00AM (MDT) 288 entrants
Blue Sky Trail Marathon (2018) (Blue Sky) Saturday, October 20, 2018 7:02AM (MDT) 339 entrants
Blue Sky Trail Marathon (2017) Saturday, October 21, 2017 7:04AM (MDT) 330 entrants