Spokane Postal Directories (Internet Archive)
Digitized collection of Polk City Directories for Spokane, Washington from 1903 through 1919. These directories were unique in that they are copies held by the main Spokane post office and used as forwarding directories.
In Spokane, the postal clerks discovered a way to make their jobs easier and also capture the information of people on the move. Each year, a city directory was unbound and interspersed with lined paper and then sewn back up again in sections. This allowed the Post Office to write in the comings and goings of Spokane residents, ensuring that the mail was forwarded to the new location. The information could be as simple as a local address change or a relocation to a different continent.