Denver, CO – Registration is now open for the 17th Denver Colfax Marathon. The race weekend will take place May 19 – 21, 2023 and the first 500 runners that register will receive the lowest prices of the season.

Race weekend events in May of 2023 are spread over three days, with 7 races taking place. The main races – the marathon, half marathon, marathon relays and urban 10 miler take place on Sunday.

The Denver Colfax Marathon is the city’s only marathon and has always been known for its scenery and unique entertainment. Runners start and finish lakeside in one of Denver’s largest city parks which is surrounded by mountains. Some of the races take runners through a working fire station and running alongside animals at the Denver Zoo.

This race weekend is Denver’s biggest running event with about 20,000 people participating every year. The marathon has one of the largest charity partner programs in the country, with over 200 non-profits using the marathon to raise funds and awareness each year.

Registration for the 2023 marathon weekend opens less than a month after the marathon’s newest race sold out. The Denver Colfax Marathon announced a new race in July – a 5k on the runway at Denver International Airport, which will take place this September.  Registration for that race filled up in less than a day, with 2500 runners getting a spot for the historic event.

To register for the May 2023 Denver Colfax Marathon, visit