25-84 inches. Tan or gray with large dark brown or black blotches down the back and a smaller series on each side; some scales yellow, orange or red producing a calico effect; underside white anteriorly, grading to gray or pale brown with obscure markings towards the tail. Young rat snakes are pale gray with dark brown blotches. Scales slightly keeled on the middle of the back, and in 25-27 rows. The Western and Gray rat snakes are distinguished on the basis of genetic differences rather than appearance. Use distribution to identify rat snake species.
Identical to those of the Western Rat Snake.
Throughout Louisiana westward to the Mississippi River floodplain. The Mississippi River forms the genetic barrier with the Western Rat Snake, but both species are known to occur on opposite sides of the River.