San Juan County is a county located in the Salish Sea in the far northwestern corner of the U.S. state of Washington. As of the 2010 census, its population was 15,769. The county seat and only incorporated city is Friday Harbor, located on San Juan Island. The county was formed on October 31, 1873, from Whatcom County and is named for the San Juan Islands, which are in turn named for Juan Vicente de Güemes, 2nd Count of Revillagigedo, the Viceroy of New Spain.It is the only county in Washington not to have state highways.HistoryThe San Juan Islands were the subject of a territorial dispute between Great Britain and the United States from 1846 to 1872, leading to the Pig War in 1859.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (72%) is water. It is the smallest county in Washington by land area and fourth-smallest by total area.San Juan County is a cluster of more than 400 islands and rocks with elevations above mean high tide. 134 of these islands and rocks are named. The county has rugged, rocky shoreline and several mountains. The highest point in the county is Mount Constitution on Orcas Island at above sea level.
