Taking place on May 15–17, 2026, the Cigna Denver Colfax Marathon marks the 20th anniversary of the Rockies’ largest running weekend—featuring a robust lineup of races: a marathon, half marathon, urban 10-mile run, 5K, and both corporate and open marathon relays, plus an expo at Empower Field at Mile High. The marathon and half courses weave through Denver’s most vibrant neighborhoods, taking runners through Mile High Stadium twice, alongside the Denver Zoo, Fire Station No. 1, Cherry Creek, Sloan’s Lake, and multiple city landmarks with panoramic mountain views. As a Boston Marathon qualifier and one of the largest marathon weekends in the U.S., the event draws over 25,000 participants, offering a festival-like atmosphere with post-race celebrations, live music, and engaging course elements.
Race Date:
16 May, 2026
The Colfax 5K kicks off the weekend on Saturday, 16 May 2026, at City Park, Denver, organized by the Colfax Marathon Partnership. This family-friendly race welcomes runners and walkers of all abilities to join the Mile-High City’s biggest running celebration.
Weather based on historical averages.
The Colfax 5K kicks off the weekend on Saturday, 16 May 2026, at City Park, Denver, organized by the Colfax Marathon Partnership. This family-friendly race welcomes runners and walkers of all abilities to join the Mile-High City’s biggest running celebration.
The Cigna Denver Colfax 5K is 5km long.
The Cigna Denver Colfax 5K takes place in Denver, CO, USA.
Runna classifies the Cigna Denver Colfax 5K elevation profile as Flat.
The best way to train for the next race is to use a personalized training plan that takes into account your current running ability, schedule, and preferences.
This will help you steadily improve your running performance and get ready for the race without risking an injury.
Check out our training plans to find the best running program for your goals!
Which plan you choose will depend on your experience, schedule, objectives, and the date of the race.
Runna offers personalized training plans for every runner and every goal: Whether this is your first, 10th or 100th race, we'll help you get the most out of your training and smash your goals.
Check out our training plans to find the best running program for your goals!
The Colfax 5K kicks off the weekend on Saturday, 16 May 2026, at City Park, Denver, organized by the Colfax Marathon Partnership. This family-friendly race welcomes runners and walkers of all abilities to join the Mile-High City’s biggest running celebration.
The Cigna Denver Colfax 5K is 5km long.
The Cigna Denver Colfax 5K takes place in Denver, CO, USA.
Runna classifies the Cigna Denver Colfax 5K elevation profile as Flat.
The best way to train for the next race is to use a personalized training plan that takes into account your current running ability, schedule, and preferences.
This will help you steadily improve your running performance and get ready for the race without risking an injury.
Check out our training plans to find the best running program for your goals!
Which plan you choose will depend on your experience, schedule, objectives, and the date of the race.
Runna offers personalized training plans for every runner and every goal: Whether this is your first, 10th or 100th race, we'll help you get the most out of your training and smash your goals.
Check out our training plans to find the best running program for your goals!
Running
Boston Marathon Qualifier
Boston Marathon Qualifier
Relay
Park
This event listing is for informational purposes only. Runna is not affiliated with, endorsed by, or sponsored by Cigna Denver Colfax Marathon 2026 or Colfax Marathon Partnership. All event details are based on publicly available information and are provided solely to help users discover running events. Runna does not use any official logos, images, or proprietary content from this event or its organiser. Any trademarks or names mentioned are used descriptively to identify the event in a factual manner. For the most accurate and up to date information (including to register or purchase an entry to the event), please visit the Cigna Denver Colfax Marathon 2026 website.