This index has over 23000 individual name entries and another 682 entries for organizations and businesses handwritten on 54 volumes of unrecorded subdivision maps located in the SMC record repository.
There are no official dates on the maps or the books that contain them, however, some odd notes and miscellaneous papers included in the books suggest that they date from 1900 to 1930.
The notes also indicate that they were kept by the County Assessors Department. In some cases names have been erased and others substituted. Some pages hold only the name of the original subdivider of the land.
aAt least three people were responsible for adding the names to the maps. One used a very clear print script, one used a relatively easy to decipher cursive script. Some names, however, were very difficult to read. The indexers did the best they could. Additionally, there were mistakes in the names themselves. You can find the same name written three ways on the same page.
Always check the map page carefully, a name was only added to the index once for each page even though they might be listed on two or more properties.
The San Mateo County Public Works Department has put the images for these maps, and an index to the places they cover, online on a page titled Unrecorded Map Index. Hit the content link for each book to open a page with all the map images from that book. You can view them online or downloaded them to your computer.
The original books are located in the County Record Repository on Tower Road
Name Index to Unrecorded Maps