Upcoming races with 100K distance in Colorado. Use filters to quickly find races by month, city or race type.
More races:ย USA running calendar
Date Race Distance Location hf:tax:monthandyear hf:tax:city hf:tax:typerace 06/07/2025 The Great Divide Ultra 100K, 100M, 25K, 50K Divide CO 06-june divide-co trail 06/21/2025 Ring the Springs 100K, 30K, 50K Colorado Springs CO 06-june colorado-springs-co trail 07/11/2025 Silverheels Trail Runs 100K, 100M, 10M, 18M, 50M, 60K Como CO 07-july como-co trail 09/27/2025 Sangre de Cristo Ultras 100K, 100M, 27K, 50K, 50M, 8M Westcliffe CO 09-september westcliffe-co trail 09/27/2025 Sangre de Cristo Trail Festival 100K, 100M, 27K, 50K, 50M, 8M Westcliffe CO 09-september westcliffe-co trail 10/04/2025 Bear Chase Race – Half Marathon 100K, 10K, 13.1M, 50K, 50M Lakewood CO 10-october lakewood-co trail
