DRG

http://topomaps.usgs.gov/drg/

A DRG is a Digital Raster Graphic, or in other words, a scanned and georectified USGS topoquad.  The DRG contains all the same information as the scanned paper map, and they are widely available for public use. The DLG above, is a scanned USGS map of a region, and contains many different features such as contours, locations, and buildings.