Cottonmouths in Mississippi: Where They Live & How Often They Bite. Mississippi is a state in the southeastern region of the United States, best known for the famous Mississippi River which is situated along its western boundary. However, Mississippi has far more to offer than just its stunning geography – with many thousands of animals calling it home. There are 55 snake species in Mississippi, six of which are venomous. The cottonmouth is a particularly abundant snake in this state. So, let’s discover everything you need to know about cottonmouths in Mississippi!