The largest snake that we have in Minnesota is the bull snake. These large non-venomous snakes, they can grow up to over eight feet long, are a subspecies of the gopher snake and are found through out the central portions of North America. They eat a variety of prey including rodents, frogs, lizards, large insects and birds. They have a reputation for having a bad temper and will often imitate a rattle snake if cornered by a large predator, such as a person. Even though they are not a water snake I found that they can swim quite well when I spotted this one crossing the St Croix River near Lake Alice.