September 13, 2026
Horsetooth Reservoir, Fort Collins, Colorado
Now Hosting the Official 2026 COMSA 1.2 Mile Open Water Championship!
Click Here to Order Exclusive Horsetooth Swims Merch! Fleece Hoodies! Beanies!
10 km Open Water Swim – Registration is closed.
1.2 mile Open Water Swim – Registration closes on 9/10/26
2.4 mile Open Water Swim – Registration closes on 9/10/26
250 meter Youth Open Water Swim – Registration closes on 9/10/26
1000 meter Youth Open Water Swim – Registration closes on 9/10/26
Other 2026 Open Water Events in Colorado:
Mountain Swim Series
- June 14, 2026 – Solstice Sunrise Swim, Longmont, CO
- July 18, 2026 – Carter Lake, Berthoud, CO
- August 1, 2026 – Willow Creek – Granby, CO
- August 22, 2026 – Castle 2.5k/5k/10k – Pine, CO
- August 23, 2026 – Wellington Swim-Run, Pine CO