Just returned from our vacation & noticed your post so hope it's not too late...
you could try calling a few of these for info and map trails. I myself ride a hybrid so do trails in area but I know a few riders who like to bike out to and around the area of High Cliff State Park.
Wheel & Sprocket...920-997-9300
Hope this helps & have fun
My parents live a short distance into the country. I found myself very comfortable on the country roads - drivers always gave me the FULL lane. Compared to biking in brooklyn this is extremely generous. Heck, by any measure its extremely generous. The area also has a robust cyclist population. It certainly doesn't have the utilitarian value it has in nyc but dedicated people are working on greenways and there are plenty to explore - http://www.focol.org/greenways/