I assume you've been able to obtain the information you requested since this post is somewhat older, but be cautious about the "attitude" you refer to in the post - State chartered banks in Wisconsin are subject to both state laws/regulations and federal laws - if you only follow federal laws that are also mandated by Wisconsin statutes, then you may be violating 99.9999% of federal banking laws (there are far more federal laws to obey than laws where Wisconsin has codified similar ones - in fact, most states's laws do not codify most federal laws, just make additional ones to further restrict activities).
The Wisconsin DFI website (http://www.wdfi.org/fi/banks/statutes.htm) has all the banking statutes PLUS the "Rules", both sets of which have items your bank must abide by. As I understand it, the "Rules" are administrative rather than statutory in nature, but still must be followed. And remember, if you can't find anything under the statutes section, there is a strong likelihood that there could be relevant material under the rules setcion.