The Sanborn maps were created to provide information to insurance companies and others about buildings, infrastructure, and other key elements of a community. We have created four Sanborn Overlays to help you see what existed at different periods in time, overlaid onto current maps or aerials. Each set of Sanborn overlay pages has two possible views: an embedded view that is contained on the page itself, and a linked view that will take you to a larger map hosted by ESRI, a Geographical Information System provider.
*Each map consists of several layers, including the underlying current aerial or map, one or more mosaic elements (see additional note below regarding mosaic elements), and buildings or other elements included in our website’s Where Are We? feature (see below). Clicking on the layer icon (
)will allow you to toggle various layers on or off.
*Moving the horizontal slider up and down will reveal or hide the base layer beneath the Sanborn map. The default view shows all of the mosaics as well as the slider that partially obscures the base layer.
*At lower right of the page is a magnifying glass. Clicking on it will open up a virtual magnifying glass so you can see a particular area in great detail.
*Link here for legends and keys that Sanborn typically used in the colored maps; link here for legends and keys for the black and white maps. These changed somewhat over time so may not be universally applicable.
*Clicking on the layer named Historic Features up to … will produce Colored dots that link to information about buildings or other historical features included in the Where Are We? feature of our website. The dots are color-coded to indicate the time frame in which the feature was added. Clicking on the dots will take you to a link for the applicable Where Are We? page.
*The basemap button thumbnail at bottom left allows you to select what you want to see under the Sanborn overlay — an aerial view or a street map.
Note re mosaic elements: Each Sanborn map series consisted of two or more sheets, with an index, or overview, page that provided an overview of the area covered by each series. Clicking on the Overview layer will toggle the Index page and show the sheet number for each area covered. Our Sanborn overlay maps were created by layering several individual sheets or groups of sheets (mosaic tiles) over a single contemporary aerial view or map. Occasionally, the mosaic elements slightly overlap and may obscure some information. Each layer can be toggled on and off with the layer button, so where there are overlapping mosaic tiles, you may wish to view each layer separately.
Please feel free to contact us at olyhistoryresearch@gmail.com for comments, queries, permissions, and questions.