Happening in mid-May, the Colfax Marathon is Denver’s only marathon and the largest marathon weekend throughout the Rocky Mountains. There are 8 races held over Saturday and Sunday, including the namesake marathon and several shorter races, a 5K, a 10-mile, and a half-marathon.
The weekend is hosted by the Colfax Marathon Partnership, a non-profit organization, from Friday to Sunday, May 16th to 18th, 2025. It was originally started by the cities of Aurora, Denver, and Lakewood to recognize Colfax Avenue, America’s longest continuously commercial street. The 26.2-mile Colfax Marathon always happens on the third Sunday in May.
Register for any of the races: 5K, Urban 10 Miler, Half Marathon, or Marathon. There is a Marathon Relay as well, which hosts more than 1,100 teams in Open, Government, and Corporate divisions.
In the last 5 years, the Colfax Marathon and its over 200 non-profit partners raised more than $3,000,000 for charities. On top of that amount, the Colfax Marathon donates over $150,000 to its charities.
Event Schedule
There is a Health & Fitness Expo held on Friday and Saturday. The first race of the event is the Colfax 5K held on Saturday (the only race on Saturday). The rest of the racing all happens on Sunday.
Friday
- Cigna Denver Colfax Marathon Expo
Saturday
- Cigna Denver Colfax Marathon Expo
- Colfax 5K
Sunday
- Marathon
- Half Marathon
- Urban 10 Miler
- Marathon Relay
- Open Relay
- Corporate Relay
- Government Relay
- Public School Teachers Relay
Need a place to stay? Pick one of the best hotels in Denver.
Details
Address: Colfax Avenue, Denver, CO
Email: info@runcolfax.org
Date: Saturday-Sunday, May 16-18, 2025
Website: runcolfax.org