[4] Built in 1957,[2] the reservoir stores water from the Middle Fork South Platte River and from a tunnel that brings water from the Blue River on the west side of the continental divide.

Most of the water entering the reservoir comes through the Hoosier Tunnel which collects water from the Blue River watershed on the west side of the continental divide and conveys it to the east side, an instance of a transbasin diversion.

[5] Because the reservoir lies near the top of the headwaters of the Middle Fork South Platte River, the watershed above the dam is rather small — only 7.7 square miles (20 square kilometers) in size,[6] so its catchment basin is limited.

The reservoir is drained by the Blue River Pipeline, a 70-mile (110-kilometer) long pipeline that flows by gravity to the Colorado Springs Utilities-owned North and South Catamount reservoirs on the slopes of Pikes Peak.

When it was built, the dam was sealed with an asphalt concrete facing.