Trail Races & Ultramarathons Near Denver, CO
As of October 6, 2026, Crewable lists 32 upcoming trail races and ultramarathons near Denver, 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 9. 2 advertise prize money.
Sources: UltraSignup, RunSignUp, UTMB, race organizers and race websites
With aid station data
13 aidin 11 days
Blue Sky Trail Marathon & Half Marathon
Fort Collins, CO3,500 ft gain
MarathonHalf Marathon
Open until Oct 17from $110
4 aid
7 aid
6 aid
3 aidRace calendar
October 2026
8 racesBlue Sky Trail Marathon & Half Marathon
Fort Collins, CO3,500 ft gainMarathonHalf MarathonOpen until Oct 17from $110
November 2026
9 racesDecember 2026
3 racesJanuary 2027
1 raceFebruary 2027
1 raceApril 2027
2 racesMay 2027
3 racesJuly 2027
2 racesThe Summit 200
Frisco, CO
August 2027
1 raceSeptember 2027
2 racesQuick answers
What is the next trail race or ultramarathon near Denver, 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 Denver?
Turkey Trails- Denver in Littleton, CO, about 9 miles from Denver, on November 7, 2026.
How many trail races and ultramarathons near Denver, CO have open registration?
9 of the 32 list registration as open as of October 6, 2026, including Blue Sky Trail Marathon & Half Marathon, Bobcat Trail Races and Indian Creek Trail Runs.
Which trail races and ultramarathons near Denver, CO offer prize money?
2 races advertise prize money, including Rocky's Backyard Ultra ($1,000).
How many of the trail races near Denver, CO are ultramarathons?
20 of the 32 are ultramarathons (longer than a marathon, or a backyard, timed or 200+ mile format). The other 12 are shorter races.
What is the busiest month for trail races and ultramarathons near Denver, CO?
November 2026, with 9 of the 32. October 2026 follows with 8.
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