100K Races in Colorado
As of October 22, 2026, Crewable lists 3 upcoming 100K races in Colorado from April 2027 to August 2027. The next is Desert RATS Trail Running Festival by UTMB on April 8, 2027 in Fruita. Registration is open for 1.
Sources: UltraSignup, RunSignUp, UTMB, race organizers and race websites
Race calendar
April 2027
1 raceMay 2027
1 raceAugust 2027
1 raceQuick answers
What is the next 100K race in Colorado?
Desert RATS Trail Running Festival by UTMB, on Thursday, April 8, 2027, in Fruita. Distances: 100K, 50K, 20K.
How many 100K races in Colorado have open registration?
1 of the 3 list registration as open as of October 22, 2026, including Desert RATS Trail Running Festival by UTMB.
What is the busiest month for 100K races in Colorado?
April 2027, with 1 of the 3. May 2027 follows with 1.
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