Upcoming Ultramarathons in Colorado

Endurance Grid lists 14 ultramarathons in Colorado, from September 2026 to July 2027 across 13 cities.

14
Races
13
Cities

The lay of the land

Ultramarathon Races in Colorado

The ultramarathon race calendar in Colorado is busiest in September, May, and June, with races most often in Bellvue, Buena Vista, and Colorado Springs.

What an ultramarathon is

An ultramarathon is any running race longer than 26.2 miles. The most common distances are the 50K, 50-mile, 100K, and 100-mile — alongside timed events, where you cover as much ground as you can in a fixed window like 6, 12, or 24 hours.

Many ultras run on trails, with aid stations stocked with food, water, and posted cutoff times. For most entrants the goal is to finish, not to race the clock, and hiking the climbs is a normal part of the day.

Frequently Asked Questions (FAQs)

How many ultramarathons are in Colorado?+
Endurance Grid's Race Calendar lists 14 upcoming ultramarathons in Colorado across 13 cities, from September 2026 to July 2027.
What ultramarathon distances are offered in Colorado?+
Ultramarathons in Colorado include 100 Mile, 100K, 10K, 4 Mile, 50 Mile, 50K, 8 Mile, Half Marathon, and more distances.
When is ultramarathon season in Colorado?+
Ultramarathon season in Colorado runs spring through fall. Of the upcoming ultramarathons on Endurance Grid's Race Calendar, the most are in September and May.
Which Colorado cities have ultramarathons?+
Ultramarathons in Colorado are held in Pine, Bellvue, Buena Vista, Colorado Springs, Como, Divide, Eaton, Granby, Larkspur, and Nathrop, plus 3 other cities.

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