Black Rock State Park is a seasonal public recreation area in Watertown, Connecticut, adjoining Mattatuck State Forest. Named for the prominent rock face overlooking Thomaston, Watertown, and parts of Waterbury, it covers 444 acres. The park began in 1926 after Black Rock Forest, Inc. donated 19 parcels totaling 254 acres, and its growth was further shaped in the 1930s by the Civilian Conservation Corps. Today, the Mattatuck Trail crosses the park, with side trails leading to views over the Naugatuck Valley, Black Rock Lake, and Black Rock Pond. The park also offers swimming, fishing, camping, and is managed by the Connecticut Department of Energy and Environmental Protection.