Red-eared slider turtle found just down the road from my house on Sunday morning, 5/22/2016. Heading out to pick up Scouts from camp, came across the turtle heading south from a pond towards a pasture. I helped her get across and set her inside the barbed wire fence.
From OK Dept of Wildlife page:
Red-eared Slider (Trachemys scripta elegans)
This is a medium-sized aquatic turtle that grows to an adult length of five to eight inches (females are larger than males). This is possibly the most abundant turtle in Oklahoma and is found nearly statewide in streams, rivers, ponds, reservoirs, marshes and sloughs. The Red-eared Slider is frequently found moving away from water and between ponds. As a result of their mobility, they readily colonize ponds and isolated bodies of water. They live in a variety of aquatic habitats, but are most common in ponds and slow-moving waters with an abundance of aquatic vegetation. Young Red-eared Sliders feed on aquatic insects, snails, crustaceans and small fish, but adult sliders are primarily vegetarian and eat aquatic plants. The most obvious physical trait of the Red-eared Slider is the presence of a bold red patch of skin behind each eye from which its name is taken. The skin color of the slider is variable. Young sliders have green skin but the color darkens as they age and very old turtles may be dark olive or nearly black skin. The shell color also is variable. Young sliders have a green shell with yellow lines and markings. The shell darkens as it matures and becomes an olive green with yellowish markings. In very old turtles, the shell is brown or nearly black and has no markings on it. The Red-eared Slider is a basking turtle and often seen lying in the sun on rocks or logs, or floating at the water’s surface.