Marathons in Colorado
Colorado is home to 3 marathons in our database in United States, spread across cities including Boulder, Denver, and Fort Collins.
Denver Colfax Marathon is the largest race in the lineup, typically drawing around 2,178 finishers, while the full spread offers everything from fast urban courses to scenic regional events.
Browse the races below for course maps, elevation profiles, typical weather, and practical race-day detail to help you choose your next start line.
Close to this race
Nearby Marathons
Other races closest to Colorado.
LaramieWyomingUnited States· 139 km away
Med Bow Rail Marathon
The Med Bow Rail Marathon draws approximately 45 finishers each May on a scenic trail road in Laramie, United States. Laramie's Med Bow Rail Marathon uses a rail-trail corridor through southeastern Wyoming's high country. The course follows the Medicine Bow Rail Trail through high-plains and mountain-foothill scenery. Rolling terrain with moderate climbs shapes the middle miles.
Next race: Sunday, 2 May 2027
CasperWyomingUnited States· 322 km away
Casper Marathon
The Casper Marathon draws approximately 89 finishers each June on a scenic road in Casper, United States. Wyoming's fast-growing Casper Marathon is a USATF-certified Boston qualifier in the heart of the state. The course follows Casper river trails, prairie roads, and wide-open Wyoming vistas. Gentle undulations are the only breaks on an otherwise flat profile.
Next race: Sunday, 6 June 2027
Green RiverWyomingUnited States· 399 km away
Run with the Horses Marathon
The Run with the Horses Marathon draws approximately 57 finishers each August on a scenic road in Green River, United States. Green River's Run with the Horses Marathon serves southwestern Wyoming on a rolling high-desert course. The course tours Green River neighborhoods and high-desert plateau roads. Rolling terrain with moderate climbs shapes the middle miles.
Next race: Sunday, 1 August 2027
DeadwoodSouth DakotaUnited States· 488 km away
Deadwood-Mickelson Trail Marathon
The Deadwood-Mickelson Trail Marathon draws approximately 238 finishers each June on a scenic trail road in Deadwood, United States. South Dakota's largest running event by participation finishes in the historic landmark town of Deadwood. The course follows the crushed-limestone Mickelson Trail through Black Hills forests, creeks, and mining-country scenery. Expect significant climbs on this hilly course.
Next race: Sunday, 6 June 2027
SpearfishSouth DakotaUnited States· 498 km away
Leading Ladies Marathon
The Leading Ladies Marathon draws approximately 125 finishers each June on a scenic road in Spearfish, United States. Spearfish's Leading Ladies Marathon is a popular June Black Hills race with a rolling scenic course. The course follows Spearfish Canyon connectors and northern Black Hills scenic roads. Rolling terrain with moderate climbs shapes the middle miles.
Next race: Sunday, 6 June 2027
CokevilleWyomingUnited States· 536 km away
Bear Lake Wyoming Marathon
The Bear Lake Wyoming Marathon draws approximately 41 finishers each August on a scenic road in Cokeville, United States. The Bear Lake Wyoming Marathon serves runners on the scenic Wyoming side of Bear Lake each August. The course tours Bear Lake basin roads with mountain and lake-country scenery on the Wyoming–Idaho border. Rolling terrain with moderate climbs shapes the middle miles.
Next race: Sunday, 1 August 2027