Marathons in Colorado
Colorado has 13 upcoming marathons scheduled for 2026. Thornton is the busiest city with 3 marathons, ahead of Fort Collins (2) and Aspen (1). The list includes Bound for Boston Marathon & Half in Denver on August 2 — Boston-qualifier marathon and half marathon.
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Frequently asked questions
What are the most popular marathon distances?▾
The most popular distances are 5K (3.1 miles), 10K (6.2 miles), half marathon (13.1 miles), and full marathon (26.2 miles). You can browse all of these distances on RACE and filter by location and date to find one near you.
How do I find a marathon near me?▾
Use the search bar on RACE to filter by your state or enter your zip code with a distance radius. You can also browse our state-by-state marathon directory to find races in your area.
When is marathon season in the US?▾
Marathon season typically peaks in spring (March-May) and fall (September-November) when temperatures are ideal for distance running. Major fall marathons include Chicago, New York City, and Marine Corps.
What is a good marathon time for beginners?▾
A common goal for first-time marathoners is to finish under 5 hours. The average US marathon finish time is around 4 hours 30 minutes. Many runners focus on simply finishing their first race rather than chasing a specific time.
How do I qualify for the Boston Marathon?▾
Boston Marathon qualifying times vary by age and gender, ranging from 3:00 for men 18-34 to 5:25 for women 80+. Many runners use fast, flat courses like Sacramento CIM or Houston Marathon as Boston qualifiers. Browse BQ-friendly races on RACE.