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Marathon directory

Marathons in Colorado, United States

100 upcoming marathons listed in Colorado across 6 cities. Next: San Juan Softie 100 on August 14, 2026.

100marathons upcoming
6cities
August 14, 2026Next race
Marathon, Half marathon, Ultra, 10K, 5K, RelayDistances
Larkspur, Colorado, United States
01MAY
ULTRA
Greenland Trail Races
Larkspur, Colorado, United States
May 1, 2027 MAY
Colorado, United States
08MAY
ULTRA
Quad Rock
Colorado, United States
May 8, 2027 MAY
Colorado, United States
15MAY
ULTRA
Denver Marathon
Colorado, United States
May 15, 2027 MAY
Divide, Colorado, United States
15MAY
42.2K
Endure Trail Runs
Divide, Colorado, United States
May 15, 2027 MAY

List your marathon with verified details

Hosting a marathon in Colorado, United States? Submit the official source for free so runners can verify the race before they plan travel.

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Already listed in Colorado, United States? Open the race and use Update listing. Missing event? Add it for free with the location prefilled.

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Cities

Place Marathons
Boulder 1
Denver 1
Leadville 1
Leadville 1
Manitou Springs 1
Manitou Springs 1

Planning notes for Colorado, United States

Use this region page to shortlist 100 upcoming races by date, distance, registration path, and official source.

  • Next raceSan Juan Softie 100 on August 14, 2026
  • Busy monthsSeptember (30), October (21), August (16)
  • DistancesMarathon, Half marathon, Ultra, 10K, 5K, Relay
  • VerifyOpen each race page, then confirm details from its official, registration, course-map, or source link.

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