Overnight RV parking MAY be ok, read reports
Catfish Bend CasinoHot
RV Parking and Camping Information
May 12, 2011
The RV parking is located north of the parking garage behind the hotel back entrance. It can get very congested in the lot when there is a convention going on in one of the halls. Upon signing up for their player's card right now you receive $10 in free play, $2 off of the restaurant and $5 in the gift shop. The gift shop doesn't sound great but we were able to stock up on drinks like tea and soda.
-report from Diane, August 2007
Another new casino in Iowa is Catfish Bend in Burlington. The casino opened in May or June and is next to Fun City. I had talked to someone who said that they allow overnight RV parking, but we haven't had the chance to visit it ourselves to be sure.