The USGS completed the primary topographic map series of the conterminous United States at the scale of 1:24,000 in 1992. Revisions were made until 2006. Alaska, Hawaii, Puerto Rico, and Trust Territories were done at other scales and will be included in...
The goal of this collection (of historical topographic maps) is to find, catalog, and georeference all topographic maps published by the USGS. The intent is to allow complete access to the content of these maps so the history documented by this...
Georeferencing means that features on the historical maps are tied to the earth's coordinate system using latitude and longitude. Georeferencing then allows the historic quadrangles to be used in a GIS system and combined with other data. Users who...
The USGS topographic maps are best known as "quadrangles." The quadrangle maps normally cover a standard unit of latitude and longitude. An example is the 1:24,000 maps that are 7.5 x 7.5 minutes. Another USGS FAQ provides a complete list of the various...