O'Fallon. Not a bad town, other than being stuck in the People's Republik, LOL!
I dunno, there were some pretty sizable settlements in Mesa Verde/Chaco Canyon area, just not much left now.
I've lived in Illinois previously, my step-grandmother was a life-long Chicagoan, her husband a political officeholder for many years. I was exposed to just enough inside dirt about Illinois politics to be supremely and rightfully contemptuous of anything and everything they say, LOL!