The park in St Charles (on the west side) is nice, Casino Queen looked good. We have not stayed at either.
We've stayed at Red Barn Rendezvous and Cahokia RV Parque, both run by good people. Cahokia and Casino Queen are only a couple miles apart, both in a rough neighborhood. However, both are fenced and Casino Queen has there own security while Cahokia has a police station at one end. These 2 are only 3 miles from the Arch.
We were there for work, 7 months. 4 months at Red Barn (5 miles from the shop we were at), right off I55 20 miles north of the city. Then they all shut down for winter and we had to move to Cahokia, the only one left open.
There is a KOA in Granite City, but they had closed for winter. The people we knew staying there said they had power problems during the hottest part of the summer. When I talked to the owner he told me about their electrical issues and showed me the updates they started for the winter, redoing all the 50 amp sites. The problem was only during 100+ degree days when the park was full. I only mention this because I was heavily warned about it by several people.
2013 DSDP 4347, all electric, 450 H.P. ISL
Air & hydraulic leveling
14 Jeep Grand Cherokee Overland toad