I had to do research to figure out what type of Turtle this is I photographed at the Sequoyah National Wildlife Refuge in Oklahoma. I believe it is a Ouachita Map Turtle.
On each side of the head, there are three large blotches that distinguish Ouachita map turtles from all our other map turtles. One is behind the eye, one below the eye, the third below the line of the mouth.
There is another Turtle called a False Map Turtle that looks a lot like this Turtle. This site (herpnet.net) does a great job of showing the difference between these two Turtles. False map turtles have a thick yellow line behind each eye that forms a backward L shape.
The Ouachita Map Turtle spends most of their day basking. Selected basking locations are seldom on or near shore. While basking, these species are wary and difficult to approach; one turtle re-entering the water due to disturbance often leads others to follow.
How I Got The Shot
I spotted this Turtle in the Arkansas River west of the Tuff Boat Ramp. I was able to park on the side of the tour road straight out from the Turtle without scaring it.
I had my Fujifilm X-T3 camera resting on a bean bag draped over the open window of my pickup with a Canon EF 100-400 mm f/4.5-5.6L IS II lens attached with a Fringer EF-FX Pro. I was shooting in aperture priority mode (AV) with a shutter speed of 1/680 of a second at f8 and the ISO at 800. I also had a 0.3 exposure value. White Balance was set on auto.