In 1890, Mill Valley’s first post office was a box in the corner of the train depot. Mail went to and from San Francisco daily. Until 1940 when the federal government constructed a building in the Spanish Mission revival architecture on Sunnyside, the post office was moved several times in the downtown area. Even the address was changed.  Between 1892 and 1904 Mill Valley was named Eastland.  In 1895 the post office was in an eight-foot by ten-foot corner in the back of a store on the corner of Throckmorton and Bernard, Wheeler Martin Grocer.  By 1906 it was in the new Keystone building. There was no delivery service.  Houses were generally referred to only by the owner’s name or by the name of the property, e.g., “The Maples”.  In 1917, the Outdoor Art Club led a petition drive to secure direct, free mail delivery. Street signs were necessary. Mailboxes or mail slots had to be installed. The numbering and displaying of Mill Valley addresses finally began. In 1919, two U.S. government postal inspectors visited. They pronounced the town ready.  Mail delivery service, originally to central Mill Valley only, began in early 1920.