The 2021 Colfax Marathon rescheduled its annual May run to October as a result of increasing COVID-19 cases in Colorado, organizers announced.

The Colfax Marathon is now scheduled for Oct. 16 and 17. Details on specific race days and start times will be released in April.

The 2020 Colfax Marathon was cancelled over COVID-19 concerns, offering runners the opportunity to participate virtually or defer registration to a later race.

The Colfax Marathon is Denver’s only marathon and the largest marathon weekend in the Rocky Mountains. The weekend hosts seven races over two days, including a marathon, half-marathon, 10-mile run, relay and 5K.

The marathon course begins in Denver’s City Park and ends in Lakewood, with runners traveling along Colfax Avenue.

Runners who deferred their 2020 registration to 2021 are automatically entered for the October race. Participants will have to confirm registration details in early 2021, at which point they can also choose to defer to 2022.

Registration for the October race will open in early 2021 for new registrants.

The 2021 race will mark the Colfax Marathon’s 15th anniversary, beginning as a way to recognize Colfax Avenue as the longest main street in the United States. The nationally recognized event garnered 20,000 runners in 2019.

The Colfax Marathon plans to return to its usual schedule in 2022, holding the race on the third Sunday of May.