This map is a counterpart to our at-risk structures map. This map is primarily meant for documenting the locations of structures that have been demolished before 1990; however, some structures that were in existence before 1942 that still exist will also appear on the map. Native American sites will not be mapped unless they are protected as a site by state or federal agencies in order to avoid our maps being used for looting.

The icons are color coded.

Gray: Structures from before 1821

Red: Structures from between 1821 and 1865.

Orange: Structures from between 1866 and 1899.

Green: Structures from between 1900 and 1941.

Purple: Structures from between 1942 and 1989.

Photographs that depict multiple structures will be categorized based up when the photograph was taken and will a similar color coded system.

Red: Photographs from before 1865.

Orange: Photographs from between 1866 and 1899.

Green: Photographs from between 1900 and 1941.

Purple: Photographs from between 1942 and 1989.

Such photographs will have a camera icon. Aerial photographs will have an airplane icon. The icon for these photographs will be pinned to approximately where the photographer took them