Marathons in Boulder, Colorado 2026

2 marathons and running events in Boulder

🏃 Boulder
Registration Open May 25, 2026
United States

BOLDERBoulder 10K

Boulder, Colorado 10K, Virtual
Certified 50,000 runners
$69.00 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 →