The 540-acre Boulder Reservoir opened in the summer of 1955. The reservoir's initial purpose was to provide irrigation water for local farms, but 75 tons of sand were brought in to create a beach that first summer, and the "Res" soon became a popular venue for swimming, fishing, and boating.
Today, the Res is a popular locale for waterskiing and for various watercraft, for families and for local students from CU. The Boulder
Reservoir now supplies the City of Boulder with some of its water (the rest coming from Barker Reservoir and the Arapaho Glacier/Silver