Can I import a US Topo into my geographic information system (GIS)?
Yes, but with many caveats. The US Topo was not intended to be a GIS product. It was designed to serve users who need medium-scale topographic and orthoimage maps, but who are not GIS users. US Topos are derived from GIS data. Almost all these data are from USGS and other government sources, and most are available for free through web services or file download sites. The US Topo represents a repackaging of these data, not new data creation. The primary design objective was to provide these data in a convenient and familiar form to people who need maps but who are not professional cartographers. The traditional 7.5-minute quadrangle layout and PDF format were selected as the best way to accomplish this objective; the GeoPDF extensions were adopted because they added some cartographic value at no cost to the end user. This repackaging actually degrades the original data, because information must be filtered and generalized to create a readable quadrangle map. This degradation is justifie
