Sanborn Fire Insurance Maps Sanborn Fire Insurance Maps show in great detail lots, houses, businesses, and other structures located in the city's central district. Originally used by insurance agents to set fire insurance rates, Sanborn Maps help date structures, find original lot and building outlines, and locate outbuildings. By comparing maps with different publication dates it is possible to see how cities and neighborhoods evolve and change over the years.
All maps are on microfilm unless otherwise stated.
Maps on rolls 1-3 are filmed in color. City Date Roll 1. City Date Roll 30. Palo Alto May 1939 Hardcopy 58. 24 City Date Roll 64.