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. Its next confirmed date is Sunday, May 16, 2027. About 25,000 runners take part across all distances.
- Race day
- May 16, 2027
- Location
- Denver, CO
- Field size
- ~25,000 runners
Race details
- Date
- Sunday, May 16, 2027
- Location
- Denver, Colorado
- Distances
- Marathon, Half, Urban 10 Miler, Marathon Relay, 5K
- Field size
- About 25,000 runners
- Course
- 183 m (~600 ft) gain
- Registration
- raceroster.com
- Official website
- runcolfax.org
Registration, course & weather
- Registration status
- Open
- Start time
- 6:30 AM MDT
- Course profile — Marathon
- Loop course; Road surface; Boston qualifier
- Course profile — Half Marathon
- Loop course; Road surface
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
More marathons in Colorado
Coming up next, by confirmed date.
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Guides from the RaceRove blog
- 8 min read How to Choose Your First Marathon A practical checklist for choosing a first marathon based on course, weather, cutoff, travel, field size and support.
- 7 min read How to Find a 5K, 10K, Half Marathon or Marathon Near You A practical way to find running races near you: pick a distance, decide how far you'll travel, read the listing properly and confirm the details before you register.
- 9 min read How to Run a Race in All 50 States How to plan a 50-state running challenge: set your own rules, group states into trips, build a calendar around the seasons, budget for it and keep track of every finish.
- Blog All guides Planning advice for finding, choosing and travelling to races.
Denver Colfax Marathon: common questions
- When is the Denver Colfax Marathon?
- The next confirmed date is Sunday, May 16, 2027.
- 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.
- Is registration open for the Denver Colfax Marathon?
- Yes — registration is open.
- What time does the Denver Colfax Marathon start?
- 6:30 AM MDT.
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.