Run a 5k, 10k, Half, or Full, at the foothills of the Rockies, in the stunning running mecca of Boulder. Run the streets Olympians train on, then celebrate at our epic after-party downtown!
Secure your spot now in Colorado’s largest fall running weekend! After nearly tripling in size last year and selling out, Boulderthon has instituted a new 5,000 runner cap this year and is expected to sell out again.
Boulderthon is a Boston Marathon Qualifying (BQ), USATF Sanctioned Event, measured by a Level A USATF Course Measurer, representing the highest level of certification for a marathon race series.
Based in Boulder, Colorado, Stronger Faster Boulder Co. is a Colorado non-profit organization and federally-recognized as a 501(c)(3) tax-exempt foundation, EIN # 84-2863972. Donations and contributions are tax-deductible as allowed by law.