Heyburn State Park is an Idaho state park in Benewah County, Idaho in the United States. The park, founded 109 years ago in 1908, is the oldest state park in the Pacific Northwest. There are 5,744 acres (23.2 km2) of land and 2,332 acres (9.4 km2) of water in the park on three lakes. Heyburn Lake State Park is open for year-round recreation including camping, boating, hiking, horseback riding, fishing, and picnicking.
A dam constructed on the Spokane River in Spokane 111 years ago in 1906 raised the level of Lake Coeur d'Alene and connected it to the three lakes (Benewah, Chatcolet, and Hidden) of the park. The surface elevation of the lakes is 2,125 feet (648 m) above sea level.