Hartford Beach State Park is a year-round South Dakota park on Big Stone Lake in the state's northeast, known for lake access and a wide range of outdoor activities including camping, cabin stays, swimming, fishing, hiking, disc golf, geocaching, and boating. It also holds an important place in the development of South Dakota's park system. In 1945, Hartford Beach became one of three parks established when the legislature created the statewide system, joining Lake Herman State Park and Oakwood Lakes State Park. Since then, it has remained a multi-use lakeside destination where water recreation and overnight stays are central.