Guernsey State Park provides the finest examples of Civilian Conservation Corps (CCC) work in the Rocky Mountain area. The park has long been known as a haven for boating, camping, hiking and picnicking, but its real treasure may lie in the wonderful CCC work that can be seen throughout the park. CCC projects in the park include hiking trails, roads, bridges, buildings (including the Castle, Brimmer Point and the Museum) and even a nine-hole golf course (which was abandoned in the early 1940s).
A dam was built between 1925 and 1927 by the Bureau of Reclamation to create Lake Guernsey. Although its waters serve primarily for irrigation purposes, they are also used by area residents and visitors alike for summer swimming, boating and fishing. The dam itself is an earthen structure with a height of 105 feet and a length of 560 feet. The original reservoir held 74,000 acre feet of water and had a surface of 2,045 acres. The power generating plant has an output of 4,800 kilowatts.
Guernsey State Park was created when the Civilian Conservation Corps (CCC) went to work in 1933. The CCC's workers completed approximately 85% of the planned project before they were disbanded in 1936.