The ODNR Division of Geological Survey has numerous 1:24,000-scale open-file maps that show the bedrock geology and bedrock topography for the state of Ohio. Most of these maps are outdated and originally were drawn on Mylar copies of USGS 7.5-minute topographic maps.
While these maps are still available, they are of lower quality than our latest print-on-demand, digital products and are superseded by maps in the Digital Map Series.
For information on availability and pricing for these historic maps, contact the Geologic Records Center at (614) 265-6576. Available maps include:
- Bedrock geology maps—Depict the distribution of bedrock units at the land surface or beneath unconsolidated sediments.
Superseded by the BG-2 series of maps.
- Bedrock topography maps—Depict the configuration and elevation of the bedrock surface as if all unconsolidated sediments had been removed.
Superseded by the BG-4 series of maps.
- Bedrock structure contour maps—Depict the changes in elevation of the upper surface (contact) of a bedrock unit in the map area.
Superseded by BG-5 series of maps.
A compendium of bedrock unit descriptions (Open-File Report 98-1) is included in all orders for bedrock geology maps. For an index to the 7.5-minute and 30-x-60-minute topographic maps, see Educational Leaflet 16: Ohio Topographic Maps.