Shaw Island is the smallest of the four San Juan Islands served by the Washington State Ferries. The island has a land area of 19.952 square kilometres (7.704 square miles) and a small year-round population of 240 (2010 census). During the summer time, weekends swell with other residents and the occasional tourist. The island is within the historical territory of the Lummi Nation. The United States obtained Shaw Island and the rest of the San Juan archipelago by treaty in 1855, but Lummi retained certain cultural and resource rights, including fishing.