Colorado · Marathon
Marathons in Colorado
Colorado currently has 15 upcoming marathons with a confirmed date listed in RaceRove. Colorado Springs, Denver, Boulder and Fort Collins have the largest concentration of events.
May (3), June (3) and September (3) are the busiest months on the calendar right now. Another 8 annual marathons are waiting for next year's date to be announced.
- Upcoming, date confirmed
- 15
- Active listings
- 23
- Cities with races
- 15
More ways to browse Colorado
Upcoming marathons in Colorado
All 15 with a confirmed date, soonest first.
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Run Through Time Trail Marathon and Half MarathonSalida, COMarathonHalf Marathon10K5K +1 more ~3,133 runners
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Bound for Boston Marathon & Half Marathon - DenverDenver, COMarathonHalf Marathon10K5K ~150 runners
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Colorado Springs Marathon, Half, 5K, and Kids KColorado Springs, COMarathonHalf Marathon10K5K +1 more ~2,500 runners
Dates come from each race's own listing. Always confirm on the organiser's site before you book travel.
Largest marathon events in Colorado
By estimated field size across all distances at the event.
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The Long View MarathonFort Collins, CO Usually held in October · next date not announcedMarathon10K5K ~6,084 runners
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Run Through Time Trail Marathon and Half MarathonSalida, COMarathonHalf Marathon10K5K +1 more ~3,133 runners
When marathons happen in Colorado
- March
- 1 upcoming race
- May
- 3 upcoming races
- June
- 3 upcoming races
- August
- 1 upcoming race
- September
- 3 upcoming races
- October
- 3 upcoming races
- November
- 1 upcoming race
Colorado cities with the most marathons
- Colorado Springs
- 3 upcoming races
- Denver
- 3 upcoming races
- Boulder
- 2 upcoming races
- Fort Collins
- 1 upcoming race
- Estes Park
- 1 upcoming race
- Fruita
- 1 upcoming race
- Leadville
- 1 upcoming race
- Manitou Springs
- 1 upcoming race
Annual events awaiting their next date
These marathons are held every year, but the next date isn't in the listing yet. The month shown is when each is usually held.
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The Long View MarathonFort Collins, CO Usually held in October · next date not announcedMarathon10K5K ~6,084 runners
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Blue Sky Trail Marathon & Half MarathonFort Collins, CO Usually held in October · next date not announcedMarathonHalf Marathon26.7 Miles13.4 Miles ~1,200 runners
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Windsor Marathon, Half Marathon, 10k, 5k & 1 Mile RunWindsor, CO Usually held in October · next date not announcedMarathonHalf Marathon10K5K +1 more ~660 runners
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Aspen Valley MarathonAspen, CO Usually held in July · next date not announcedMarathon10K5K ~222 runners
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Aspen BackcountryAspen, CO Usually held in August · next date not announced50 KilometerMarathonHeavy Half Marathon ~123 runners
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Staunton Rocks! Marathon and Half MarathonPine, CO Usually held in August · next date not announcedMarathonHalf Marathon10K5K ~112 runners
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Durango MarathonDurango, CO Usually held in October · next date not announcedMarathonHalf Marathon5K
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West Elk ChallengeCrawford, CO Usually held in October · next date not announced30K OptionTrail Marathon
Marathons in nearby states
Guides from the RaceRove blog
- 8 min read How to Choose Your First Marathon A practical checklist for choosing a first marathon based on course, weather, cutoff, travel, field size and support.
- 7 min read How to Find a 5K, 10K, Half Marathon or Marathon Near You A practical way to find running races near you: pick a distance, decide how far you'll travel, read the listing properly and confirm the details before you register.
- 4 min read Diplo's Run Club 2026-27: Every City, Date and Course Diplo's Run Club is a 5K with a post-race concert. Every US date for 2026-27 (San Francisco, New York, Los Angeles, San Diego and Phoenix), start times and courses.
- Blog All guides Planning advice for finding, choosing and travelling to races.
Marathons in Colorado: common questions
- How many marathons are there in Colorado?
- RaceRove currently lists 15 upcoming marathons in Colorado with a confirmed date, plus 8 annual events whose next date hasn't been announced yet.
- How long is a marathon?
- A marathon is 26.2 miles (42.2 kilometres).
- Which Colorado cities have the most marathons?
- By upcoming events listed in RaceRove: Colorado Springs (3), Denver (3), Boulder (2), Fort Collins (1) and Estes Park (1).
- When is marathon season in Colorado?
- Of the upcoming marathons listed, the busiest months are May (3), June (3) and September (3).
- What is the biggest marathon in Colorado?
- By estimated field size, the largest event with a marathon listed in Colorado is the Denver Colfax Marathon, with about 25,000 runners across all of its distances.
Search every marathon in Colorado
Filter by month, course profile and field size, save races to a shortlist and compare them side by side in the interactive search.