Officials of the Denver Colfax Marathon and its associated races are making course changes this year which they say are necessary to accommodate more runners.
Race weekend sold out in 2023 with 21,000 runners and walkers in the marathon, half marathon, marathon relays, 10-miler and 5K, according to the event’s chief executive, Andrea Dowdy, making it the largest marathon weekend in the eight-state Rocky Mountain region.
Race weekend this year is May 17-19, and Dowdy said early registration is already ahead of last year’s record pace.
“We’re really excited,” Dowdy said of the course alterations and the need for them. “It allows us to welcome more runners every year, and we’re super excited that the sport of running in Denver is so popular and so many people love the Colfax experience.”
Several miles where marathoners and half marathoners previously shared the course will be separated this year, expanding overall racer capacity.
For half marathoners, there will be a new route through the Denver Zoo and a new route through downtown utilizing Speer Boulevard. The new zoo mile will be wider and will showcase the zoo’s new Down Under exhibit, which will open later this year.
Marathon runners will no longer have to share the Cherry Creek bike path with half marathoners because the half marathoners will be on adjacent Speer. Marathoners and half marathoners also will be separated into two lanes on 17th Ave., 17th St. and Lawrence St. Details of the new courses are available at the .
