Colorado · Marathon · Half · Urban 10 Miler
Denver Colfax Marathon
Denver Colfax Marathon is a marathon, half marathon, Urban 10 Miler, Marathon Relay and 5K event held in Denver, Colorado. It is usually held in May; the exact date hasn't been confirmed in the listing yet. About 25,000 runners take part across all distances.
- Usually held
- May
- Location
- Denver, CO
- Field size
- ~25,000 runners
Race details
- Usually held in
- May (date not confirmed)
- Location
- Denver, Colorado
- Distances
- Marathon, Half, Urban 10 Miler, Marathon Relay, 5K
- Field size
- About 25,000 runners
- Course
- Mostly flat urban course (~5,280 ft altitude)
- Registration
- raceroster.com
- Official website
- runcolfax.org
About the Denver Colfax Marathon
Held over a full weekend along Denver's historic Colfax Avenue, this is the city's largest running event with a marathon, half, Urban 10 Miler, relay and 5K. The 2026 edition marks the 20th anniversary and expects more than 25,000 runners.
Rankings and notes
- Rankings and awards
- Denver's only marathon and the city's biggest race weekend; 20th anniversary in 2026; USATF-certified Boston-qualifier; course passes a full mile through the Denver Zoo
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Denver Colfax Marathon: common questions
- When is the Denver Colfax Marathon?
- The next date hasn't been announced in the listing yet. The race is usually held in May. Check the organiser's website for the official date.
- Where is the Denver Colfax Marathon held?
- In Denver, Colorado.
- What distances does the Denver Colfax Marathon offer?
- Marathon, Half, Urban 10 Miler, Marathon Relay and 5K.
- How many people run the Denver Colfax Marathon?
- About 25,000 runners across all of its distances. That figure is an estimate of the field size, not an entry cap.
- How do I register for the Denver Colfax Marathon?
- Registration is handled by the organiser at raceroster.com. Entry fees, caps and deadlines are set there.
Plan this race in RaceRove
Save it to your plan, compare it with other races, check typical race-day weather and track your 50-state progress in the interactive app.