This map turtle was on the move, probably looking for a nesting site although I didn't check to see if it was a female.
The northern map turtle is named for the markings on its shell, which look like the contour lines on a topographical map.
Northern map turtles inhabit large rivers and lakes with slow-moving water and a soft bottom. They require high-quality water that supports the female’s mollusc prey.
Female northern map turtles may take more than 10 years to reach maturity. They nest from June through July and lay a single clutch of up to 17 eggs. They hatch in the fall, and in some cases the hatchlings overwinter in the nest. The incubation temperature of the eggs determines the gender of the hatchlings.