SwimCO
Castle 5K/10K
August 22, 2026 • Bailey, CO
Course Distances
10K
5K
2.5K
About this race
The Castle 5K/10K is the highest altitude organized marathon swim event in the country at ~8,000 feet. It is hosted at Wellington Lake, near Conifer in Colorado. 2.5K, 5K and 10K swims are available.
Register now at WebsiteMore from Mountain Swim Series
Complete the series or find your next challenge