Colorado Triathlon Calendar 2025-2026

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Explore the best triathlons in Colorado for 2025-2026! Our updated list features 338 exciting races across the region. Find your next race in Colorado below and join the running community at these great events!

May 2025
May
3
Saturday

Take 5 in The Garden

Trail Run 5 km 5 mi
May
3
Saturday

Greenland Trail Races

Trail Run 4 mi 8 mi 25 km 50 km
May
3
Saturday

Collegiate Peaks Trail Run

Trail Run 25 mi 50 mi
May
3
Saturday

Hayden Cog Run

5 km 8 mi
May
3
Saturday

Falcon 50 - Colorado Springs

Trail Run 13 mi 26 mi 50 mi
May
3
Saturday

Newbie to 5K

5 km
May
3
Saturday

Adams County Foster Care 5K Run/Walk

5 km
May
3
Saturday

The Best Races - Aurora

5 km 10 km 13 mi
May
3
Saturday

The Best Races - Centennial

13 mi
May
4
Sunday

Colorado Marathon

5 km 10 km 13 mi 26 mi
May
4
Sunday

Longmont Half

5 km 13 mi
May
4
Sunday

Altitude Elementary Moose Mudder

Obstacle Run 5 km
May
4
Sunday

Fairmount 5k

5 km
May
4
Sunday

RMRR Trophy Series

5 km 5 mi
May
4
Sunday

Water Wells for Africa 5k Walk/Run

5 km
May
6
Tuesday

Dash & Dine 5k

5 km
May
10
Saturday

Valkyrie Trail Race

Trail Run 4 mi 8 mi ... 26 mi 50 km
May
10-11
Sa - Su

Adventure Fest at 18 Road

Trail Run 13 mi 22 km 50 km
May
10
Saturday

Niwot's Challenge

Trail Run 24 mi 50 mi 100 mi
May
10
Saturday

Mountain Ridge Trail Race

Trail Run 5 km 10 km 13 mi 21 mi
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