Run Boulderthon: The Boulder Marathon
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Run Boulderthon: The Boulder Marathon
Run Boulderthon is a multi-distance race weekend held in Boulder, Colorado, scheduled for September 27, 2026. The event is staged in the foothills of the Rockies below the Flatirons and concludes with a downtown finish and an after party in Pearl Street area. The course is measured by a Level A USATF Course Measurer and the series is USATF sanctioned and Boston Marathon qualifying.
The event includes multiple distances:
- Full Marathon
- Half Marathon
- 10K
- 5K
- Kids Run
The race series reported drawing over 15,000 runners from all 50 states and 18 countries in 2024 and has grown substantially since its inception. It has received recognition from outlets such as Runner's World, Active, and USA Today, which have placed the event among national lists for fall races and top half marathons and 5K events. Post-race reporting from participants notes strong recommendation rates, with 95% of surveyed runners citing the downtown finish and course views as top reasons for recommending the event. Organizers describe a combination of large-race amenities and a setting focused on the natural and urban features of Boulder. Visit the organization's website for the most recent information.
