FYI:
Rockford IL is sometimes considered a far NW suburb of Chicago...
I hope it wasn't Woodfield Mall in Shaumburg. I shop there whenever I go to Chicago. A friend and I were planning on heading there next weekend.
Here in the NW suburbs of Chicago, we do not consider Rockford to be part of the greater metropolitan area, but it does have a decaying rustbelt feel to it. (No offense intended to Rockfordians).
That's only because Chicago denies that anything in Illinois exists outside of Chicago
Only by the MSM! No self-respecting downstater would consider Rockford a suburb of Chicago! :-) There are a LOT of cornfields between Chicago and Rockford!
I lived in Rockford for three years. It's the 2nd largest city in IL and no one knows of it because it's almost always lumped in with Chicago for many demograhic purposes. For better or worst, people in both cities know better.
Rockford has an airport with a runway large enough to land the Concorde (I was there when it stopped for a visit) and plenty of room to expand and _should_ be used to relieve the crowding at O'Hare but since Chicago couldn't collect tax in Rockford the idea always gets squashed.
Rockford IL is to Chicago as Madison WI is to Milwaukee.