Saturday, Oct 18, 2025 at 7:00am
Taking place on the trails between Horsetooth Mountain Park and the Devil’s Backbone Open Space, the Blue Sky courses take you on a north-south tour of the easternmost hogbacks of Northern Colorado’s Front Range mountains. With a moderate amount of elevation gain and loss and a variety of terrain, 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 cut-offs 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 dirt road (no motor vehicle access) and gravel trail, 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 BBQ, awards and generous sponsor giveaways.
Event Schedule:
5:30-6:45am - Marathon Race Day Packet Pickup
6:50am - Marathon Pre-Race Briefing
7:00am - Marathon Start
9:30a-4:00pm - Finish Line BBQ
10:00am - Blue Sky Aid Cut-Off – Marathon
11:30am - Overall Marathon Awards. Age Groups Offered on a Rolling Basis
12:30pm - Indian Summer South Aid Southbound Marathon Cut-Off
1:00-4:00pm - Half Marathon Pre-Race Packet Pickup
1:45pm - Indian Summer South Aid Northbound Marathon Cut-Off
4:00pm - Finish Cut-Off
Time Cut-Offs
Marathon course cut-offs will be enforced at the following aid stations:
Blue Sky Aid Station (mile 9.2) at 10:00am. 3:00 total time.
Indian Summer South outbound (mile 15.6) at 12:30pm. 5:30 total time.
Indian Summer South inbound (mile 20.3) at 1:45pm. 6:45 total time.
Awards
All runners who finish within the official course cut-off will receive a unique finisher’s award.
We acknowledge and respect those who experience their gender identity in ways outside of the traditional male/female dichotomy, and are trying our best to provide non-binary opportunities in both the registration and results to reflect that. Currently, we are offering non-binary recognition for the top 3 overall in that category, and will expand to age groups as participation levels grow.
1st, 2nd, and 3rd Place Overall Awards for the top male and female finishers in each distance.
Age Group Awards for the top 3 male and female in each of the following age groups (overall winners not eligible) for both distances:
Under 40
40 to 49
50 to 59
60 and Over
As well as 1st-3rd Overall for the non-binary category.
Additional Dates: