Ohio has abundant freshwater resources, including our shared portion of Lake Erie on the north "shore", the Ohio River on the south, and many beautiful lakes, rivers, and streams across the state.

There is a natural divide between the streams and rivers that empty into Lake Erie and those that empty into the Ohio River. Can you guess where this divide is located?
See: http://www.great-lakes.net/lakes/

The colored area surrounding the Great Lakes is the Great Lakes watershed*. So the water that falls on this land drains into one of the Great Lakes. The surface water from the Great Lakes watershed empties into the Atlantic Ocean through the St. Lawrence River. The water that drains into the Ohio River system empties into the Mississippi River and eventually the Gulf of Mexico.For example, Cleveland, which is on the south shore of Lake Erie, is part of the Great Lakes watershed. On the other hand, Columbus, located in the central part of Ohio, is part of the Ohio River watershed. So although these two cities are only 145 miles apart, the rain that falls on them will enter the Atlantic Ocean and the Gulf of Mexico about 2000 miles apart.

*Notice that the watershed does not include area that would drain into the St. Lawrence Seaway.

Just as there is a divide between the Great Lakes and Ohio River watersheds in Ohio, there are divides between the drainage basins of Ohio's rivers.

(Source: Gazetteer of Ohio Streams Second Edition August 2001. Click to enlarge)

This map is very complicated because of the number of lines. If you print it and color one river's watershed or drainage basin (using the code given), it may become more clear.

Some of these rivers have been designated as "state" and "national scenic rivers."
About National "Wild and Scenic Rivers" http://www.nps.gov/rivers/about.html

Ohio's National Scenic Rivers:
Ohio has 3 rivers that have been designated as National Scenic Rivers.
Big and Little Darby Creeks http://www.nps.gov/rivers/wsr-big-darby.html
Little Beaver Creek http://www.nps.gov/rivers/wsr-little-beaver.html
Little Miami River http://www.nps.gov/rivers/wsr-little-miami.html

Information about Ohio's scenic rivers act:
http://www.ohiodnr.com/dnap/sr/#sract

Ohio's state scenic rivers are indicated on this map:
http://www.ohiodnr.com/dnap/sr/
Also available form this website is are links to Ohio Stream Flow Data, Stream Quality Monitoring, and the Sampling Stations for the Olentangy River.