Algonac State Park lies on the St. Clair River about two miles north of Algonac and spans 1,550 acres, including a half mile of river frontage on a busy international shipping route. Established in 1937, it grew through additional land purchases and began development in the 1940s. Much of the park remains undeveloped, preserving rare Michigan lake plain prairies and savannas known as oak openings. These natural areas provide habitat for 22 species of plants, birds, and butterflies classified by the state as endangered, threatened, or of special concern. The park is also valued for freighter watching, walleye fishing, and varied outdoor recreation.