Colorado Marathon Calendar 2025-2026

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Explore the best marathons in Colorado for 2025-2026! Our updated list features 18 exciting races across the region. Find your next race in Colorado below and join the running community at these great events!

March 2026
Mar
14
Saturday

Run Through Time Trail Marathon

Trail Run 2 mi Half Marathon Marathon
April 2026
Apr
25
Saturday

Runs With Scissors Races

Half Marathon Marathon 50 km
May 2026
May
3
Sunday

Colorado Marathon

5 km 10 km Half Marathon Marathon
May
9
Saturday

Valkyrie Trail Race

Trail Run 4 mi 8 mi ... Marathon 50 km
May
15-17
Fr - Su

Denver Colfax Marathon

10 mi 13 mi 26 mi
May
16
Saturday

Endure Trail Runs

Backyard Ultra 10 km Half Marathon Marathon 12 hr
May
30-31
Sa - Su

Weld Your Mettle Running Festival

Backyard Ultra 4 mi 14 mi ... 100 km 100 mi
June 2026
Jun
6
Saturday

Summits Trail Runs

Trail Run 6 mi 13 mi 26 mi 50 km
Jun
7
Sunday

Steamboat Marathon

10 km Half Marathon Marathon
Jun
27
Saturday

Leadville Trail Marathon and Heavy Half

Trail Run 15 mi 26 mi
July 2026
Jul
18
Saturday

Silverton Alpine Runs

Trail Run 8 mi Marathon 50 km
Jul
19
Sunday

Aspen Valley Marathon

5 km Half Marathon Marathon
August 2026
Aug
1
Saturday

Aspen Backcountry Marathon

Trail Run Half Marathon Marathon 50 km
Aug
8-9
Sa - Su

Emerald Mountain Epic

Trail Run 13 mi 26 mi
September 2026
Sep
19-20
Sa - Su

Pikes Peak Marathon

Trail Run 13 mi 26 mi
Sep
19-20
Sa - Su

Pikes Peak Ascent

Trail Run 13 mi 26 mi
Sep
27
Sunday

Run Boulderthon: The Boulder Marathon

5 km 10 km Half Marathon Marathon
October 2026
Oct
3
Saturday

Colorado Springs Marathon

5 km Half Marathon Marathon
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