13 aidin 11 days
Blue Sky Trail Marathon & Half Marathon
Fort Collins, CO3,500 ft gain
MarathonHalf Marathon
Open until Oct 17from $110
Trail Races & Ultramarathons Near Fort Collins, CO
As of October 6, 2026, Crewable lists 12 upcoming trail races and ultramarathons near Fort Collins, CO from October 2026 to September 2027. The next is Rocky's Backyard Ultra on October 10 in Estes Park, CO. Registration is open for 3. One advertises prize money.
Sources: UltraSignup, RunSignUp, UTMB, race organizers and race websites
With aid station data
13 aid
7 aid
1 aid
1 aidRace calendar
October 2026
3 racesBlue Sky Trail Marathon & Half Marathon
Fort Collins, CO3,500 ft gainMarathonHalf MarathonOpen until Oct 17from $110
November 2026
3 racesDecember 2026
2 racesJanuary 2027
1 raceTwin Mountain Trudge
Laramie, WY
February 2027
1 raceMay 2027
1 raceSeptember 2027
1 raceQuick answers
What is the next trail race or ultramarathon near Fort Collins, CO?
Rocky's Backyard Ultra, on Saturday, October 10, 2026, in Estes Park, CO. Distances: Backyard Ultra.
What is the closest trail race or ultramarathon to Fort Collins?
Blue Sky Trail Marathon & Half Marathon in Fort Collins, CO, about 1 mile from Fort Collins, on October 17, 2026.
How many trail races and ultramarathons near Fort Collins, CO have open registration?
3 of the 12 list registration as open as of October 6, 2026, including Blue Sky Trail Marathon & Half Marathon, Colorado 24 Hour Run and Louisville Trail Race.
Which trail races and ultramarathons near Fort Collins, CO offer prize money?
One race advertises prize money: Rocky's Backyard Ultra ($1,000).
How many of the trail races near Fort Collins, CO are ultramarathons?
8 of the 12 are ultramarathons (longer than a marathon, or a backyard, timed or 200+ mile format). The other 4 are shorter races.
What is the busiest month for trail races and ultramarathons near Fort Collins, CO?
October 2026, with 3 of the 12. November 2026 follows with 3.
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