100K races in Colorado

The 9 100K ultramarathons in Colorado, with each one's climb, cutoff and date. Every race links to its own page, where you can see how it fits the runner you are now.

Race	Distance	Where	Date	Climb	Cutoff
Sangre de Cristo 100K	100K	Westcliffe, CO	Sep 26, 2026	12,400 ft	24 h
The Bear Chase 100K	100K	Lakewood, CO	Oct 3, 2026	4,336 ft	16 h
Desert RATS 100K	100K	Fruita, CO	Apr 10, 2027	6,632 ft	20 h
The Great Divide Ultra 100K	100K	Divide, CO	Jun 5, 2027	8,500 ft	22 h
Weld Your Mettle Running Festival	100 KM	Windsor, CO	Jun 5, 2027	—	24 h
Ring the Springs 100K	100K	Colorado Springs, CO	Jun 19, 2027	11,000 ft	22 h
Silverheels 100K	100K	Como, CO	Jul 9, 2027	11,000 ft	24 h
Never Summer 100K	100K	Gould, CO	Jul 24, 2027	14,500 ft	24 h
Telluride Mountain Run 65 Mile	65 Mile	Telluride, CO	Aug 21, 2027	22,500 ft	32 h