Horsetooth Reservoir has more of a boating than a swimming culture.

However, on hot summer days, the cool mountain water feels pretty amazing.

Swimming is permitted in Horsetooth Reservoir in two places. The South Bay day use area has pretty much everything, from a boat launch to camping to scuba and swimming.

Further north, on the east side of the Reservoir is Sunrise day use area. Swimming, and other day use activities are also allowed here.

All of these areas require day passes or annual permits (totally worth it).

For information on Horsetooth Reservoir and Horsetooth Mountain Park, click here.

Though Horsetooth is beautiful and the waters feel amazing, the park gets very crowded on the weekends and holidays.

My favorite times to swim (or be) there is on weekdays. Midweek and 2pm, and you'll have the place all to yourself. Weekends and evenings, there will probably be boat traffic going to and from.