Just do the opposite; found this on another thread.
Bike via Madison streets, trails to Glacial Drumlin, through Waukesha to New Berlin, down through the Oak Leaf, to the Racine Trail, on the Root River pathway through Racine, pick up the Racine County trail to Kenosha, the Kenosha lakefront to the Kenosha/Robert McClory/Green Bay, take Asbury to Washington to Elmwood in Evanston and then weave south on residential streets, pick up Chicago Lakefront trail at Loyola Park.
You'll need to have Google Earth installed on your machine, at least, if you don't have a GPS or Garmin Mapsource. If you use a GPS on your bike you'll have to turn off the automatic routing so that your unit doesn't screw up the trails.
Otherwise get a hold of Bob Kastigar if you're looking for the western route.
Great to hear! It took alot of research and planning to put that together - we all used 700X28C tires minimum and took on the gravel the whole way. The waypoints or camping sites are all marked in the gpx/kml also.... I'd like to head through downtown Milwaukee next year.
I angled up from Delvan through Whitewater and Fort Atkinson and then found the Glacial Drumlin trail somewhere. I used county roads but sorry I do not have my route. The roads in Wisconsin are in good shape and most of the highways have at least a 4 foot shoulder (unlike Iowa). Remember a day on the Wisconsin bike paths costs $4.00 and a season $20.00. Hope you have good weather.