Castle 2.5K/5K/10K 2025

Distances and entry

• 2.5k — $107.02
• 5k — $128.22
• 10k — $138.82

About Castle 2.5K/5K/10K 2025

THIS EVENT HAS PASSED, REGISTER FOR CASTLE 2.5K/5K/10K 2026

The Castle 2.5K/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.

Sign up to Volunteer

Race Day Schedule will be shared closer to event date.

Distances:

• 2.5K

• 5K

• 10K

T-shirts are not guaranteed. We close t-shirts around 2 weeks before the race.

If you plan on Camping, but have already signed up for the race, please click on “SHOP” above. This will allow you to select a camping site for Friday night (August 22), Saturday night (August 23), or for both nights (August 22 & 23).  Camp Sites will fit 1 vehicle and 4 persons only. No RVs, trailers, or teardrop campers, cars/trucks only.

We will close online registration when we have reached our parking cap for this race (250 participants)

All packet pickup will be the morning of the swim. Please plan to come and pick up your packets early!

Early Bird Registration Closes March 1. Race prices will become full price on that date.