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Marathons in Colorado, United States

156 upcoming marathons listed in Colorado across 7 cities. Next: Denver Marathon on May 15, 2027.

156marathons upcoming
7cities
May 15, 2027Next race
Marathon, Half marathon, Ultra, 10K, 5K, RelayDistances

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13JUN
21.1K course — Arvada, Colorado, United States
All-Out Summer Breeze
Arvada, Colorado, United States
June 13, 2026 JUN
14JUN
42.2K course — Aspen, Colorado, United States
Aspen Valley Marathon
Aspen, Colorado, United States
June 14, 2026 Certified
20JUN
21.1K course — Windsor, Colorado, United States
Red, White and Brew 5k, 10k & Half Marathon
Windsor, Colorado, United States
June 20, 2026 JUN
20JUN
ULTRA course — Lake City, Colorado, United States
San Juan Solstice 50
Lake City, Colorado, United States
June 20, 2026 JUN
20JUN
21.1K course — Georgetown, Colorado, United States
Slacker Half Marathon-Relay-4-Mile Races
Georgetown, Colorado, United States
June 20, 2026 to June 27, 2026 JUN
20JUN
21.1K course — Centennial, Colorado, United States
Sloth Run 5K/10K/13.1 DENVER/AURORA
Centennial, Colorado, United States
June 20, 2026 JUN
21JUN
42.2K course — Estes Park, Colorado, United States
Estes Park Marathon & Half Marathon 2026
Estes Park, Colorado, United States
June 21, 2026 JUN
25JUN
ULTRA course — Alma, Colorado, United States
Race in the Clouds - Alma Dirt Festival 2026
Alma, Colorado, United States
June 25, 2026 JUN
27JUN
ULTRA course — Colorado, United States
Denver Pride
Colorado, United States
June 27, 2026 JUN
27JUN
21.1K course — Georgetown, Colorado, United States
Slacker Half Marathon-Relay-4-Mile Races
Georgetown, Colorado, United States
June 27, 2026 JUN
27JUN
42.2K course — Glenwood Springs, Colorado, United States
The Sunlight Showdown
Glenwood Springs, Colorado, United States
June 27, 2026 JUN
28JUN
ULTRA course — Idaho Springs, Colorado, United States
Blue Sky Ascent & Round Trip (formerly the Mt. Evans Ascent)
Idaho Springs, Colorado, United States
June 28, 2026 JUN
03JUL
ULTRA course — Colorado, United States
The Rundola
Colorado, United States
July 3, 2026 JUL
04JUL
21.1K course — Castle Rock, Colorado, United States
5th Annual July 4th ROCK-IT RUN
Castle Rock, Colorado, United States
July 4, 2026 JUL
04JUL
ULTRA course — Colorado, United States
Hahn’s Peak Hill Climb
Colorado, United States
July 4, 2026 JUL
04JUL
21.1K course — Centennial, Colorado, United States
July 4th Run 5K/10K/13.1 DENVER/AURORA
Centennial, Colorado, United States
July 4, 2026 JUL
04JUL
ULTRA course — Colorado, United States
Vail HillClimb Trail Run
Colorado, United States
July 4, 2026 JUL
10JUL
ULTRA course — Colorado, United States
Chase the Moon
Colorado, United States
July 10, 2026 JUL
10JUL
ULTRA course — Colorado, United States
Hardrock Hundred Mile Endurance Run
Colorado, United States
July 10, 2026 JUL
10JUL
ULTRA course — Colorado, United States
Silverheels 100
Colorado, United States
July 10, 2026 JUL
10JUL
ULTRA course — Como, Colorado, United States
Silverheels Trail Runs
Como, Colorado, United States
July 10, 2026 JUL
11JUL
21.1K course — Westminster, Colorado, United States
All-Out Dog Days
Westminster, Colorado, United States
July 11, 2026 JUL
11JUL
ULTRA course — Estes Park, Colorado, United States
Estes Park's Backyard Ultra
Estes Park, Colorado, United States
July 11, 2026 JUL
11JUL
21.1K course — Littleton, Colorado, United States
Heatwave Half Marathon - Denver
Littleton, Colorado, United States
July 11, 2026 JUL

Cities

Place Marathons
Aspen 1
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 156 upcoming races by date, distance, registration path, and official source.

  • Next raceDenver Marathon on May 15, 2027
  • Busy monthsAugust (30), July (30), September (30)
  • 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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