Graham’s crayﬁsh snake averages 18 to 28 inches in length. Its back is brown or dark olive, and a broad, yellow stripe is present along each lower side. The belly is yellow and may or may not have markings. The scales are keeled (ridged).
Graham’s crayfish snake may be found throughout Illinois except in those counties that border the Wabash and Ohio rivers. It is not abundant in any area. This snake lives in ponds, streams, sloughs, swamps and marshes. Graham’s crayfish snake is semiaquatic. It hides under stones or debris along the water’s edge and sometimes in crayfish burrows or other burrows. It basks on rocks and in branches overhanging the water. It is active in the day except in the hot summer months when it becomes nocturnal. This snake may flatten its body when disturbed and/or release large amounts of bad-smelling musk from glands at the base of the tail. It overwinters in crayfish burrows or other burrows. Mating occurs in April or May. The female gives birth to from 10 to 20 young in late summer, the number depending on her size and age. Graham’s crayﬁsh snake mainly eats crayfish that have just shed their exoskeleton but will also take other crustaceans, amphibians and ﬁshes.