Boulderthon Half Marathon is expected to sell out. Over 4,000 runners are expected at this year’s Boulderthon from 50 states and 13 countries, with registrations coming in over 2x the rate of last year. 5k, 10k, Full Marathon are Nearing Capacity. Register today.
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.