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Researching Your Leadville House

Sanborn Maps

The Sanborn Maps were created for fire insurance companies to use to assess their liabilities. These maps depict residential, commercial and industrial areas in cities and towns across the U.S., Canada, and Mexico. Our collection just consists of the maps for Leadville for the years 1883, 1886, 1889, and 1895. Contact Aj Brokaw for access to the maps

The Sanborn Maps show the size, shape, and construction of buildings as well as street names, property boundaries, and building use. They may be used for a variety of purposes, including environmental site assessment, architecture, urban history, and genealogy.

The Library of Congress has a wonderful collection and more in depth information about the Sanborn Maps available on their website. Their maps are in color, and they also have a complete set for 1937 Leadville..

Searching the Sanborn Maps

Using the same 318 W. 4th St. address, the Sanborn Map didn't reach that area in 1883, so we will start with 1886. In the Sanborn Maps, you want to look at the first page as this will tell you which page has the area you want to view.

The above image is the first page of the Sanborn Map for 1886. Each large bold number is the page number, so for 318 W. 4th St. we will want page 13, see page below.

Now we are in the right area, so we will zoom in to see 318 W. 4th, below.

Here is the neighborhood where 318 W. 4th is located. You may be wondering what all the symbols mean. The first page of the Sanborn Map has a key, see below.


Here is an even more zoomed in view of 318 W. 4th St. Using the key we can see that the house is a frame building, where the door is (round shape facing 318 on the street), the house is one story (represented by the number 1), has a shingle roof (x), and in some parts a slate or tin roof (o). The abbreviation B.C. is not included in the key but stands for brick chimney.

This is the Sanborn Map of Leadville from 1895 that has 318 W. 4th. Below is the key and a zoomed in view of the house.


As you can see the house didn't change very much from 1886 to 1895. It remained a dwelling (D), is a frame building (yellow), still one story (1), and has a shingle roof (x).

Helpful Links

The map keys do not always contain all of the symbols you encounter on a Sanborn Map. Luckily there are several helpful resources available out there to help you. These are links and resources that we have found to be particularly helpful:

EDR's Handy Sanborn Legend -

        A very popular tool that is easy to download and even print.

Historical Info Gathers - Description and Utilization of the Sanborn Maps - Edited by David Hodnefield -
        Compiled from the 1940 and 1953 Editions. Still useful for older maps.

Library of Congress - Introduction to the Collection (Sanborn)

        Great information in the about section, but also in the articles and essays.