Horsetooth Reservoir

This is an artificial lake, it is still one of the best places to go swimming in Colorado. This multi-purpose reservoir is used to supply water to the town of Fort Collins, and to help with irrigation in the lower South Platte River Basin, although it also attracts its fair share of swimmers and recreational enthusiasts in the summer. Swimming is only permitted in two places the South Bay and the Eastern Swim Beach. Because this is the primary swimming hole for Fort Collins, it can be very crowded during the weekends. However, if you show up during the week you might be lucky to have the entire beach to yourself.