Ultramarathons Near Fort Collins, CO
As of October 6, 2026, Crewable lists 8 upcoming 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 2. One advertises prize money.
Sources: UltraSignup, RunSignUp, UTMB, race organizers and race websites
Race calendar
October 2026
3 racesBlue Sky Trail Marathon & Half Marathon
Fort Collins, CO3,500 ft gainMarathonHalf MarathonOpen until Oct 17from $110
November 2026
2 racesDecember 2026
1 raceMay 2027
1 raceSeptember 2027
1 raceQuick answers
What is the next 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 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 ultramarathons near Fort Collins, CO have open registration?
2 of the 8 list registration as open as of October 6, 2026, including Blue Sky Trail Marathon & Half Marathon and Colorado 24 Hour Run.
Which ultramarathons near Fort Collins, CO offer prize money?
One race advertises prize money: Rocky's Backyard Ultra ($1,000).
What is the busiest month for ultramarathons near Fort Collins, CO?
October 2026, with 3 of the 8. November 2026 follows with 2.
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