Colorado 13er Half Marathon
Nine of the 13.1 miles run on flat crushed gravel outside Boulder, with Flatirons views the whole way and altitude as the only real obstacle.
Every link above goes to the race, its timing provider, or an official registration partner. Last checked July 28, 2026.
Quick facts
- Roughly nine miles on flat crushed gravel path, with Flatirons views throughout.
- Run near 5,300 feet, so visiting runners should plan for altitude.
- Ten water stations and live timed results, fields near 105 to 150 finishers.
- Early 6:30 a.m. start to stay ahead of Colorado summer sun.
2027 Colorado 13er Half Marathon registration
Registration for the 2027 Colorado 13er Half Marathon runs through the official registration page at runsignup.com.
About the Colorado 13er Half Marathon
Formerly branded around a women's apparel sponsor, this Louisville race has settled into its own identity as a well supported June half for runners of every level. Fields sit near 105 to 150 finishers, and the organizers put a lot of effort into aid, communication and timing.
Course
A looped route through Louisville with about nine miles on flat crushed gravel path and the rest on pavement, laid out to keep the Flatirons in view. Ten water stations and five toilet stops along the way, plus iced towels at the finish. The surface is kind, but the elevation near 5,300 feet is not.
Race-day weather
Early June on the Front Range means a cool 6:30 start in the 50s and a fast climb once the sun is up. Thin dry air at altitude makes hydration and a conservative first few miles matter for visiting runners.
Past Colorado 13er Half Marathon dates and results
| Year | Date | Status | Results |
|---|---|---|---|
| 2027 | Sunday, June 6, 2027 | Upcoming | — |
Colorado 13er Half Marathon FAQ
When is the Colorado 13er Half Marathon?
The 2027 Colorado 13er Half Marathon is on Sunday, June 6, 2027.
How do I register for the Colorado 13er Half Marathon?
Register for the Colorado 13er Half Marathon through the official registration link: marathonscout.com/go/colorado-13er-half-marathon/register. It opens the race registration page at runsignup.com.
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