The KOA in Union, is about 30-minutes west of the racetrack. Might be your best bet as there is easy access on and off I-90. Would not want to drag a trailer much closer to that especially with all of the race/chicago traffic. We stayed there on our way back from Minnesota in July, it was hot, a little dusty(gravel roads), but it was CLEAN!! We had a good time there, plus there is a railway museum really close by if you are into trains.
2015 Rushmore Springfield
Disc Brake upgrade, Goodyear G614 tire upgrade
RV FLEX-ARMOR roof, Mor-Ryde IS suspension
2017 F350 Dually 4x4 6.7 Bronze Fire