The Seattle-Everett Interurban Railway Routes, Then And Now (snohomishcountywa.gov) The data for this map was gleaned from maps in Warren Wing’s To Seattle By Trolley, from a 1910 Plat Book of Snohomish County. from a Thomas Guide map, from an interview with retired interurban motorman Walt Shannon, and by the author, Fred Bird.
It is best known as the island Amelia Earhart and Fred Noonan were searching for but failed to find when they and their airplane disappeared on July 2, 1937, during their planned round-the-world flight.