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.
female participant running in Boulderthon


Boulderthon® has established an athlete elite program to bring world-class athletes in from our own backyard, to runners from all over the globe with special incentives. If you are male with a Marathon PR of 2:40 (Half: 1:10 PR) or female with a Marathon PR of 3:15 (Half: 1:25 PR), please contact us at for more information, and include a link to your PR.