I know that wisconsinhighways.org hasn't been updated in years, but I stumbled upon statetrunktour.com and the people who run the site are documenting almost every state highway in Wisconsin. I haven't seen anyone talk about this site on the forum and don't know if people see the site or not, but I'm pretty impressed by it. Just wanted to promote it for other people to check it out because the people on the site have fun documenting the state highways they drive on, and it's a great site to get an in depth look at many of the state highways in Wisconsin.
I'm friends with the creator of the site. He's a great guy and a lot of fun to talk roads with. He's managed to be able to get paid for taking road trips! :-)