The United States has ten protected areas known as national seashores and four known as national lakeshores, which are operated by the National Park Service, an agency of the Department of the Interior. National seashores and lakeshores must be established by an act of the United States Congress. National seashores and lakeshores are coastal areas federally designated as being of natural and recreational significance as a preserved area. The first national seashore, Cape Hatteras, was established in 1953, and the first national lakeshore, Pictured Rocks, was established in 1966. The newest national lakeshore or seashore is Canaveral, established in 1975. All of the national lakeshores are on Lakes Michigan and Superior, and nine of the ten national seashores are on the Atlantic Ocean, including two on the Gulf of Mexico.
National seashores are located in ten states and national lakeshores are in three other states. Florida, North Carolina, and Michigan each have two. Point Reyes is the only national seashore on the Pacific coast. The largest national seashore or lakeshore is Gulf Islands, at over 137,000 acres (550 km2); the smallest is Indiana Dunes, at 15,000 acres (61 km2). The total areas protected by national seashores and lakeshores are approximately 595,000 acres (2,410 km2) and 229,000 acres (930 km2), respectively.