Fig. 1- Known distribution of the timber rattle- Fig. 2 - Known distribution of the massasauga 



snake, Crotalus horridus , in Illinois. rattlesnake, Sistrurus catenatus . in Illinois. 



Fig. 3 - Known distribution of the copperhead, Fig. 4- Known distribution of the cottonmouth, 



Agkistrodon contortrix . in Illinois. Ag kistrodon piscivorus . in Illinois. 



