Moraine Hills State Park is an Illinois state park on 2200 acre in McHenry County, Illinois, United States.

History

The McHenry dam was constructed in 1907 on the Fox River near McHenry, Illinois. The dam was donated to the state in 1924 and a new dam was built in 1934. McHenry Dam State Park was founded in 1939 with the purchase of 15 acres of land on the east bank of the river. Property on the west bank of the river was donated to the state Division of Water Resources in the early 1960s. In 1971, the state began to acquire land surrounding Lake Defiance, then constructed park facilities in 1975. Renamed Moraine Hills State Park, the park was opened to the public in October 1976.