High Quality Content by WIKIPEDIA articles! Washington State Ferries, owned and operated by the Washington State Department of Transportation, serves communities on Puget Sound and in the San Juan Islands. It is the largest fleet of passenger and automobile ferries in the United States and the third largest in the world.The ferry system has its origins in the "Mosquito Fleet", a collection of small steamer lines serving the Puget Sound area during the later part of the nineteenth century and early part of the 20th century. By the beginning of the 1930s, two lines remained: the Puget Sound Navigation Company (known as the Black Ball Line) and the Kitsap County Transportation Company. A strike in 1935 forced the KCTC to close, leaving only the Black Ball Line.