From Ohio History Central
The map turtle (Graptemys geographica) gets its name from the yellow lines on its carapace that look like roads on a map. It was named in 1816, by Charles-Alexandre Lesueur, a scientist and naturalist. He originally described it as a "Lake Erie Tortoise."
They prefer habitats that include deep, slow-moving waters, such as large rivers and lakes with muddy bottoms. Map turtles are very social and often sun themselves, sometimes stacking one on top of the other. When frightened they will quickly slip back into the water.
Map turtles breed between May and July, producing 12 to 14 eggs per clutch. They will sometimes lay two clutches per year. Upon maturity, this common reptile will reach a length of 4 - 6.33 inches for males and 7 - 10.75 inches for females.
Typical foods include freshwater clams, snails and crayfish.
They are one of the last turtles to go into hibernation. Map turtles have been seen at times even walking under the ice.
A relative of the common map turtle, the Ouachita map turtle, is found in southern Ohio section of the Scioto River. They are rare and it is unknown if they are native to Ohio. Map turtles are often caught and sold as pets, although the state of Ohio has specific laws and guidelines regarding this matter. The Ouachita may be turtles that have been unwanted and released.