Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. San Juan County is a county located in the Salish Sea in the far northwestern corner of the U.S. state of Washington. It comprises most of the San Juan Islands. The County is named after San Juan Island, which was reportedly named after St. John the Baptist by the Spanish explorer Francisco de Eliza, in 1791. The area that now constitutes San Juan County was part of Whatcom County until October 31, 1873. The county seat and the county''s only incorporated city is Friday Harbor, on San Juan Island. The 2000 Census reported a population of 14,077 for San Juan County. It is the smallest of Washington''s 39 counties in land area. According to the U.S. Census Bureau, the county has a total area of 621 square miles (1,609 km²).Of this, 175 square miles (453 km²) of it is land and 446 square miles (1,156 km²) of it (71.84%) is water.