Changes Come After Marathon’s Top Races Sold Out in 2023

Denver, CO – The 18th Denver Colfax Marathon, presented by Cigna Healthcare, is making some exciting changes to its 2024 race courses. These changes will take the running experience to the next level for thousands of people that take part in its annual race weekend.

“The Denver Colfax Marathon is now the largest marathon weekend in the 8-state Rocky Mountain region,” said Andrea Dowdy, CEO of the Denver Colfax Marathon. “We have one of the most scenic race routes in the country. From the mountains to water views, the iconic local landmarks to the unbeatable entertainment along each race, the magic of the marathon weekend is about to get even better.”

After a sold-out race weekend in 2023 with 21,000 runners, race registration continues to grow and is in high demand this year. To accommodate this and elevate runner experience, the marathon has separated its marathon course (marathon/marathon relay/10 miler) and the half marathon course for several miles of the race. Both courses will now have more runner capacity for years to come.

“Our goal every year is to make this running event a memorable weekend for each runner,” said Creigh Kelley, Race Director for the Denver Colfax Marathon. “The 2024 course changes have resulted in the best courses and runner experience to date, and runners will feel the positive impact of these changes on race day.”

The half marathon runners will see the biggest changes in their run through the Denver Zoo. The new route will have runners experience exhibits such as the brand new Down Under and the Flamingo Habitat, along with wider pathways. The Denver Colfax Marathon half marathon offers runners the most unique experience in the country with the longest race through a zoo.

“We love that Denver Zoo is a big part of what makes the Denver Colfax Marathon such a unique and memorable event, and excited that this year’s runners will be among the first to catch a glimpse at our newest animal habitat—and hopefully learn about our mission to help save wildlife,” said Jake Kubie, Director of Integrated Communications at the Denver Zoo.

Marathon course runners will also feel a big difference on race day. They will now “own” the Cherry Creek Bike Path and no longer merge with the half marathon course and runners. The Marathon and half marathon courses are now separated into 2 lanes for several miles on Lawrence and 17th Street, allowing faster marathon course runners to have a dedicated lane.


The Denver Colfax Marathon weekend will take place May 17 – 19, 2024. The city’s largest running event is expected to welcome over 50,000 people to the city in May. You can register for a race at

Detailed Course Changes for the 2024 Denver Colfax Marathon Weekend:

Half Marathon Changes:

          Runners will experience a new course through the Denver Zoo and be some of the first to see the new Down Under Exhibit featuring kangaroos, wallabies and more

          The Denver Zoo has wider pathways and in return, half marathon runners will have more space to run in their own personal safari

          New route through downtown – running through Denver Fire #1, then runners will be on Speer Blvd for a wider course, with a great view of DCPA, the famous “dancing aliens”. They’ll have a view of the Cherry Creek Bike Path from above

Marathon/Marathon Relay/Urban 10 Changes:

          Marathon course runners (marathon, urban 10 miler, marathon relay) will now “own” the Cherry Creek Bike Path and no longer merge with the half marathon course/runners

          Extended course through the Glens neighborhood

          Marathon and half marathon course are separated into 2 lanes for several miles on Lawrence and 17th, enabling faster marathon course runners to have a dedicated lane.