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Marathons in Colorado, United States

145 upcoming marathons listed in Colorado across 6 cities. Next: Blue Sky Ascent & Round Trip (formerly the Mt. Evans Ascent) on June 28, 2026.

145marathons upcoming
6cities
June 28, 2026Next race
Marathon, Half marathon, Ultra, 10K, 5K, RelayDistances
Blue Sky Ascent & Round Trip (formerly the Mt. Evans Ascent)
28JUN
ULTRA
Blue Sky Ascent & Round Trip (formerly the Mt. Evans Ascent)
Idaho Springs, Colorado, United States
June 28, 2026 JUN
The Rundola
03JUL
ULTRA
The Rundola
Colorado, United States
July 3, 2026 JUL
5th Annual July 4th ROCK-IT RUN
04JUL
21.1K
5th Annual July 4th ROCK-IT RUN
Castle Rock, Colorado, United States
July 4, 2026 JUL
Hahn’s Peak Hill Climb
04JUL
ULTRA
Hahn’s Peak Hill Climb
Colorado, United States
July 4, 2026 JUL
July 4th Run 5K/10K/13.1 DENVER/AURORA
04JUL
21.1K
July 4th Run 5K/10K/13.1 DENVER/AURORA
Centennial, Colorado, United States
July 4, 2026 JUL
Vail HillClimb Trail Run
04JUL
ULTRA
Vail HillClimb Trail Run
Colorado, United States
July 4, 2026 JUL
Colorado, United States
10JUL
ULTRA
Chase the Moon
Colorado, United States
July 10, 2026 JUL
Hardrock Hundred Mile Endurance Run
10JUL
ULTRA
Hardrock Hundred Mile Endurance Run
Colorado, United States
July 10, 2026 JUL
Colorado, United States
10JUL
ULTRA
Silverheels 100
Colorado, United States
July 10, 2026 JUL
Silverheels Trail Runs
10JUL
ULTRA
Silverheels Trail Runs
Como, Colorado, United States
July 10, 2026 JUL
Westminster, Colorado, United States
11JUL
21.1K
All-Out Dog Days
Westminster, Colorado, United States
July 11, 2026 JUL
Estes Park, Colorado, United States
11JUL
ULTRA
Estes Park's Backyard Ultra
Estes Park, Colorado, United States
July 11, 2026 JUL
Littleton, Colorado, United States
11JUL
21.1K
Heatwave Half Marathon - Denver
Littleton, Colorado, United States
July 11, 2026 JUL
Colorado, United States
11JUL
ULTRA
Silver Rush 50 Run
Colorado, United States
July 11, 2026 JUL
Colorado, United States
12JUL
ULTRA
Crag Crest Trail Run
Colorado, United States
July 12, 2026 JUL
Colorado, United States
12JUL
ULTRA
Evergreen Mountain Trail Race
Colorado, United States
July 12, 2026 JUL
Colorado Springs, Colorado, United States
12JUL
21.1K
Heatwave Half Marathon - Colorado Springs
Colorado Springs, Colorado, United States
July 12, 2026 JUL
Colorado, United States
18JUL
ULTRA
Aspen Valley Marathon
Colorado, United States
July 18, 2026 JUL
Aspen, Colorado, United States
18JUL
ULTRA
Audi Power of Four Trail Run
Aspen, Colorado, United States
July 18, 2026 JUL
Colorado, United States
18JUL
ULTRA
Spring Creek Memorial
Colorado, United States
July 18, 2026 JUL
Castle Rock, Colorado, United States
18JUL
21.1K
Summer Splash Prairie Dog Half, 10k, & 5k
Castle Rock, Colorado, United States
July 18, 2026 JUL
Buena Vista, Colorado, United States
18JUL
ULTRA
TransRockies Run Charity Bibs
Buena Vista, Colorado, United States
July 18, 2026 JUL
Colorado, United States
19JUL
ULTRA
Barr Trail Mountain Race
Colorado, United States
July 19, 2026 JUL
Colorado, United States
19JUL
ULTRA
Kendall Mountain Run
Colorado, United States
July 19, 2026 JUL

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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 145 upcoming races by date, distance, registration path, and official source.

  • Next raceBlue Sky Ascent & Round Trip (formerly the Mt. Evans Ascent) on June 28, 2026
  • 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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