Colorado Triathlon Calendar 2025-2026

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Explore the best triathlons in Colorado for 2025-2026! Our updated list features 351 exciting races across the region. Find your next race in Colorado below and join the running community at these great events!

April 2025
Apr
11-13
Fr - Su

Desert Rats Trail Running Festival

Trail Run 10 km 21 km 50 km 100 km
Apr
11
Friday

Denver Distance Classic

3 km
Apr
12
Saturday

Boulder Rez Half

5 km 10 km 13 mi
Apr
12
Saturday

RMRR Spring Marathon Training Series

10 mi 20 mi
Apr
12
Saturday

Run Through The Decades Half - Colorado Springs

6 km 7 km 8 km 13 mi
Apr
13
Sunday

Spring Fling Prairie Dog Half Marathon

5 km 10 km 13 mi
Apr
13
Sunday

Three Creeks Half Marathon

13 mi
Apr
13
Sunday

Platte River Half-Marathon

13 mi
Apr
13
Sunday

Horsetooth Half Marathon

13 mi
Apr
13
Sunday

Dash for Detection: Oral Cancer Awareness 5K

5 km
Apr
19
Saturday

Rattler Trail Race

Trail Run 10 km 25 km 50 km
Apr
19
Saturday

All-Out Beat the Heat

5 km 10 km 13 mi
Apr
19
Saturday

Rock Hawk

Trail Run 5 km 10 km 25 km 50 km
Apr
19
Saturday

Great Western Trail Race

Trail Run 5 km 10 km 13 mi
Apr
19
Saturday

Most Eggcellent 10K

5 km 10 km
Apr
19
Saturday

Can't Be Mad Running Festival

Trail Run 5 km 10 km 3 hr
Apr
19
Saturday

Woody's Tortoise and Hare

5 km
Apr
19
Saturday

The Best Races - Aurora

5 km 10 km 13 mi
Apr
20
Sunday

The Mile High 4.20K Run

4 km
Apr
26
Saturday

Bigfoot Half Marathon

5 km 13 mi
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