Background
A Digital Raster Graphic (DRG) is a scanned image of a USGS quadrangle map. The image inside the map neatline is georeferenced to the surface of the Earth.

There are 793 1:24,000 Scale DRGs covering the State of Ohio.
 
Distribution & Format
DRGs available free of charge through the GIS Service Bureau in GeoTIFF format.
 
Download
DRGs for the State of Ohio can be downloaded for free. 
DRGs can be downloaded from the following address.

Web Address: http://geodata.oit.ohio.gov/geodatadownload/data.aspx 

DRGs are also available from the United States Geological Survey (USGS)