Description: This theme shows the county boundaries for the State of Ohio. Boundaries were assembled from individual USGS Quadrangle digital line graph files (dlg) of the boundary layer (bd). These files were obtained from the GIS Support Center, Ohio Department of Administrative Services and were originally prepared by the Ohio State University Center for Mapping in cooperation with the United States Geological Survey with additional funding from several state agencies and other groups. These files were augmented in a few instances with hand digitizing where small missing line segments were found. The Lake Erie shoreline and islands in Lake Erie were added from the Hydrography layer (hy). It should be noted that because the quadrangles used varied over a wide rangle of years this line does not represent a particular water level and is for illustrative purposes only. For example there is a wide offset between the shoreline on the Metzger Marsh Quadrangle and that of the Oak Harbor Quadrangle. This distance is so large that no attempt was made to edgematch the two quadrangles. The line connecting the two shorelines represents the quadrangle boundary. For the purposes of this map Sandusky Bay and Muddy Creek Bay were included as a part of Lake Erie. The Lake Erie shoreline is not meant to represent any Lake Erie shoreline which may be used for regulatory puposes. An updated boundary for Fairfield-Licking-Perry Counties within Buckeye Lake was included by digitizing the boundary from a more recently updated quadrangle map. Conversion from the dlg format to ArcInfo was accomplished using ArcInfo software in conjuction with an AML program to adjust the quadrangles so that their corners fall on the exact coordinates of the quadrangle corners. Due to the way in wihich coordinates are stored in the dlg's there is some variation in the quadrangle corner coordinates.
Copyright Text: Ohio Department of Natural Resources