St. Croix State Park is a state park in Pine County, Minnesota, USA. The park follows the shore of the St. Croix River for 21 miles (34 km) and contains the last 7 miles (11 km) of the Kettle River. At 33,895 acres (13,717 ha) it is the largest Minnesota state park. It was developed as a Recreational Demonstration Area in the 1930s. 164 structures built by the Civilian Conservation Corps and the Works Progress Administration survive, the largest collection of New Deal projects in Minnesota.