Marathons in Colorado, United States 2026

12 marathons and running events

Cities

Aspen 1 Boulder 1 Boulder 2 Denver 1 Denver 1 Fort Collins 1 Fort Collins 1 Leadville 1 Leadville 1 Manitou Springs 1 Manitou Springs 1
🏃 Fort Collins
Registration Open May 3, 2026
United States

The Colorado Marathon

Fort Collins, Colorado Full Marathon, Half Marathon, 10K, 5K
BQ Certified 3,500 runners
$120.00 entry View Details →
🏃 Fort Collins
Registration Open May 3, 2026
United States

Colorado Marathon (Fort Collins to Poudre Canyon)

Fort Collins, Colorado Full Marathon, Half Marathon, 10K
BQ Certified 2,800 runners
$90.00 entry View Details →
🏃 Denver
Registration Open May 17, 2026
United States

Denver Colfax Marathon

Denver, Colorado Full Marathon, Half Marathon, 5K, Relay
BQ Certified 22,000 runners
$100.00 entry View Details →
🏃 Boulder
Registration Open May 25, 2026
United States

BOLDERBoulder 10K

Boulder, Colorado 10K, Virtual
Certified 50,000 runners
$69.00 entry View Details →
🏃 Aspen
Registration Open Jun 14, 2026
United States

Aspen Valley Marathon

Aspen, Colorado Full Marathon, Half Marathon, 10K
Certified 1,400 runners
$100.00 entry View Details →
🏃 Leadville
Featured Aug 15, 2026
United States

Leadville Trail 100 Run

Leadville, Colorado Ultra Marathon, 100 miles (160km)
750 runners
$350.00 entry View Details →
🏃 Manitou Springs
Featured Aug 16, 2026
United States

Pikes Peak Marathon

Manitou Springs, Colorado Full Marathon, Half Marathon
750 runners
$110.00 entry View Details →
🏃 Leadville
Registration Open Aug 22, 2026
United States

Leadville Trail 100 Run

Leadville, Colorado Ultra Marathon
500 runners
$195.00 entry View Details →
🏃 Manitou Springs
Registration Open Sep 20, 2026
United States

Pikes Peak Marathon

Manitou Springs, Colorado Full Marathon
1,600 runners
$175.00 entry View Details →
🏃 Boulder
Featured Oct 4, 2026
United States

Boulder Marathon

Boulder, Colorado Full Marathon, Half Marathon, 10K
BQ Certified 3,800 runners
$85.00 entry View Details →
🏃 Denver
Featured Oct 18, 2026
United States

Denver Marathon

Denver, Colorado Full Marathon, Half Marathon, 10K
BQ Certified 9,000 runners
$85.00 entry View Details →
🏃 Boulder
Registration Open Dec 5, 2026
United States

ColderBOLDER 5K

Boulder, Colorado 5K
Certified 2,500 runners
$32.00 entry View Details →