Physiographic Regions of Ohio
This is a great color map that denotes the physiographic regions of the state of Ohio.
Source: Department of Natural Resources

Ohio Outline Map
This is a basic black and white map showing the county lines as its only details.
Source: Indiana State University

Annual Average Precipitation Map
This map shows the average annual rainfall in the state.
Source: Spatial Climate Analysis Service, Oregon State University

Ohio State Map
If you need a map that shows the major freeways in Ohio, this is it!
Source: World Sites Atlas

Ohio City and County Maps
Click on the name of the city or county you want to see to reveal a detailed street map of the area.
Source: Ohio Department of Transportation

Merriam Webster Atlas
This atlas page shows the Ohio state map and some quick facts. There is also a good explanation of the symbolism of the state flag.
Source: The New York Times and Merriam Webster