12 Hours Ultra Running Events in Colorado

All 50 KM 50 Miles 100 KM 100 Miles 6 Hours 12 Hours 24 Hours

Date	Event	City	Distances
06/06/26	Haul Ass Ultra Running Festival	Erie	6 Hours , 9 Hours , 12 Hours , 50 KM , 50 Miles
06/27/26	Chase the Moon Endurance Run	Highlands Ranch	6 Hours , 12 Hours , 50 KM
07/18/26	Thumbs Up Summer Slam	Estes Park	12 Hours
09/03/26	Front Range Ultra Dayze	Loveland	12 Hours , 24 Hours , 48 Hours , 100 Hours , 50 KM , 100 Miles , 200 Miles
09/05/26	Raising the Barr	Brighton	6 Hours , 12 Hours
11/07/26	Colorado 24 Hour Run	Fort Collins	6 Hours , 12 Hours , 24 Hours
05/15/27	Endure Trail Runs	Divide	12 Hours

Date	Event	City	Distances
05/30/26	Weld Your Mettle Running Festival	Windsor	6 Hours , 9 Hours , 12 Hours , 24 Hours , 36 Hours , 48 Hours , 50 KM , 50 Miles , 100 KM , 100 Miles
04/11/26	Run the Ranch	Loveland	6 Hours , 12 Hours
02/06/26	Running Up for Air Pine - Staunton Rocks	Pine	6 Hours , 12 Hours , 24 Hours
10/18/25	Sheriff's Shootout	Mancos	6 Hours , 12 Hours
07/19/25	Powderhorn Mountain Ultra and Vert Challenge	Mesa	6 Hours , 12 Hours
06/21/25	Red, White, and Brew (12 Hour "Last Person Standing" Race)	Windsor	12 Hours , 50 Miles
05/24/25	The Ol' College Try 24 Hour Ultra	Denver	6 Hours , 12 Hours , 24 Hours
01/18/25	Resolve to Run 5K & Ultra Challenge	Greeley	12 Hours
10/23/21	Fox Run Endurance Run	Colorado Springs	12 Hours , 50 Miles
10/02/21	Bear Creek Endurance Run	Colorado Springs	5 Hours , 10 Hours , 12 Hours
09/11/21	Fountain Creek Endurance Run	Fountain	12 Hours
08/28/21	Lincoln Mountain Endurance Run	Larkspur	6 Hours , 12 Hours
10/03/20	Tommyknocker 12-Hour & Mine Shaft Half	Golden	12 Hours , 50 KM , 100 KM
07/06/18	Steep Camp (Silverton 1000)	Silverton	6 Hours , 12 Hours , 24 Hours , 48 Hours , 72 Hours , 144 Hours , 100 Miles
10/11/14	24 Hours of Boulder	Boulder	6 Hours , 12 Hours , 24 Hours , 50 KM , 100 KM , 100 Miles
06/29/13	Silverton 6/12/24 Hour Mountain Runs	Silverton	6 Hours , 12 Hours , 24 Hours