There are several resources for locating geospatially coded data and maps for use with GIS software. Additionally, there are clearinghouse resources which provide users with the opportunity to browse data available from commercial and government sources.
OGRIP - Ohio Geographically Referenced Information Program - provides spatial data sets available to download. Map types include DLG, DOQ, DRG and DEM.
GIMS - Geographic Information Management Systems sponsored by the Ohio Department of Natural Resources.
OhioLink Landsat 7 Satellite Image Server - provides satellite imagery of the state of Ohio.
State or County Level GIS Data - free data from the GIS Data Depot. You must first setup a user account to access files. Most GIS files are in Interchange File format (.E00) which can easily be converted to Coverage or shapefile using ArcGIS (ArcView 8x Tools).
Global or Country Level GIS Data - free data from the DIVA-GIS. GIS files are in shapefile format. GRID raster image files are also available.
Census 2000 TIGER/Line Data - TIGER/Line files are extracts of selected geographic and cartographic information from the Census Bureau's TIGER (Topographically Integrated Geographic Encoding and Referencing) database. The files have been converted to shapefile format by ESRI.
Digital Raster Graphics (DRGs) - are scanned, georeferenced topographical maps. The maps are projected using the local UTM coordinates, and are registered to the collars.
Digital Elevation Models (DEMs) - raster data sets that provide users with spot elevation readings at discrete distances. The standard DEM has a 30-meter resolution.
Digital Line Graphs (DLGs) - vector based data files that display features found on a USGS topographic map. Not all areas of the country have had DRGs produced as of yet, and some areas have only partial data. The hypsography layer of DLGs will provide users with contour lines.
Digital Orthophoto Quadrangle (DOQ) - computer-generated image of an aerial photograph. It has been orthorectified--altered so that it has the geometric properties of a map. The standard DOQ from the USGS is a black & white or color-infrared image covering 3.75 minutes of latitude by 3.75 minutes of longitude. Four DOQs can be combined to cover the area represented by a standard USGD 7.5-minute, 1:24,000-scale topographic map.