WA-List » San Juan County

San Juan County


  • Name origin: Named for Juan Vicente de Güemes (1740-99), viceroy of New Spain.
  • Established: 1873 Oct 31
  • County seat: Friday Harbor
  • County government website
  • Upcoming events (via WA-List’s events calendar)
  • Population (2010): 15,769 (Rank: 32 of 39)
  • Area (2010): 173.92 square miles (Rank: 39 of 39)
  • Density (2010): 90.7 people per square miles (Rank: 11 of 39)
  • Highest elevation: 2,407 feet, Mount Constitution.


Cities and Towns Incorp. Population Area Density Elevation Zip code
(sq miles) (pop/sq miles) (feet)
1. Friday Harbor town 1910 2,162 2.09 1,034.4 100 98250


Additional facts

  • San Juan County is one of six Washington counties with only one incorporated city.
  • San Juan is the smallest county in the state by land area.
  • Orcas (57.3 square miles), San Juan (55.0 square miles), and Lopez (29.8 square miles) are the 2nd, 3rd, and 7th largest islands in the state.


  • This page is updated periodically in an effort to keep information accurate and offer additional data.
  • = link to map
  • All population and area data are from the 2010 United States Census. All population density figures for cities greater than 5,000 people are as well. Densities of smaller towns and cities were calculated separately using US Census data.