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.
marathon participants and tents in Boulder Reservoir

START & FINISH MAPS

Marathon and Half Marathon Start Area Map

Boulder CO Marathon start area map

Most updated version as of 9/20/22

10K Start Area Map

Boulder CO 10K start area map

Most updated version as of 9/20/22

Finish Area Map

Boulderthon Expo Map

Most updated version as of 1/3/22