San Juan Island National Historical Park, also known as American and English Camps, San Juan Island, is a U.S. National Historical Park owned and operated by the National Park Service on San Juan Island in the state of Washington. The park is made up of the sites of the British and U.S. Army camps during the Pig War, a boundary dispute over the ownership of the island. The camp sites were designated a National Historic Landmark in 1961, and listed on the National Register of Historic Places in 1966. The park was created by an act of Congress in 1966 and expanded slightly in 2013.