I live in Iowa too. Let me know where your searching for herps and what your finding. Have you see the web site: http://www.herpnet.net
It has a good accounting of Iowa herps. There is also the Iowa Herp Society, although in my experince they have shown little interest in native Iowa herps. Unfortunately they tend to focus on "showy" herps like boas and pythons.
There are many great opportunities to study herps in Iowa. Keep up your studies and you'll have an opportunity to catch snakes for a living!
As far as watersnake bites go: They do bleed a lot. I have had allergic reactions to the bite of a Florida Blue garter and have seen people react to Iowa red-sided garters. When I was a kid we always saw bites as a badge of courage - silly macho stuff. But I still feel a fondness toward the Nerodia and Thamnophis musk - ahhhh, smells like spring!
Joe