Here's how to watch, road closures to look out for, and everything you need to know for this weekend. 

The Colfax Marathon is returning to Denver after 880 days, and it's set to be a memorable event for everyone involved. The city's largest running event was last held on May 19, 2019. When the marathon, half-marathon, 10-mile race, and City Park 5K return on October 16–17, it'll be the largest running event in the state since the Bolder Boulder Memorial Day Race in 2019. About 14,000 people are scheduled to run in the races this weekend!

The Colfax Marathon normally takes place on the third Sunday in May, but the COVID-19 pandemic delayed the race until October 2021. Event organizers plan to host the event on its regularly scheduled day next May as well. 

Colfax isn't the only race affected by the pandemic. The Chicago Marathon returned last weekend after being canceled last year, and the Boston Marathon took place this week as well—though it's normally held in April. 

Denver's major marathon race will feature a new half-marathon course that will reduce the number of road closures in various neighborhoods. The old course took runners east from City Park and to Montview Boulevard in Aurora. The new course instead heads west from City Park toward a downtown loop like the marathon course and returns to City Park. The marathon course heads west to Lakewood and back to City Park. 

The half-marathon will also start at the same time as the marathon and the marathon relay at 6:45 a.m. The 10-mile race will start in Lakewood at 9 a.m. and finish in City Park. 

To adhere to safety measures in place due to COVID, entry points will be larger than usual, and finisher medals will be handed to racers instead of putting over their heads by volunteers. Volunteers also won't hand runners drinks; runners will grab them off the tables while racing by. 

If you're not running the race or cheering on a friend, here are the major road closures to be aware of on October 16: 

  • York Street between E. Colfax Ave. and E. 23rd Ave: Closed between 6:30 a.m. and 8 a.m.
  • E. 23rd Ave. between York Street and Colorado Blvd.: Closed between 6:30 a.m. and 8:15 a.m.
  • E. 17th Ave. between Detroit and York Streets: Closed between 6:30 a.m. and 10 a.m.
  • E. Colfax Ave. Westbound between Elizabeth Street and Speer Blvd.: Closed to vehicles between 7 a.m. and 10 a.m.
  • W. Colfax Ave. Westbound between I-25 and Garrison Street in Lakewood: Closed between 7:30 a.m. and noon. 
  • Raleigh Street between Colfax Ave. to E. 17th Ave.: Closed between 7:30 a.m. and 9:30 a.m.
  • At least one lane of Lawrence Street between Speer and E. 17th St., E. 17th St. to E. 17th Ave., E. 17th Ave. to Vine St.: Closed between 7:30 a.m. and 1 p.m.
  • Vine St. between E. 17th to 22nd Ave.: Closed to north-to-south vehicle traffic between 7:30 a.m. and 1:30 p.m.
  • One-lane only on E. 22nd Ave. between Vine and Gaylord St. 
  • Gaylord St. between E. 22nd and 21st Ave.: Closed between 7:30 a.m. and 1:45 p.m.

Visit for more information on event times and road closures. 

Are you planning to run or watch the race this weekend? Let us know in the comments.