I was looking at the website for Sparta last night, and there was a message on it saying that the 2010 Grand event was sold out. There are 2 campgrounds nearby on the way to the Pioneer Cabin (we went there for dinner 2 days ago). I will try to find the names of them and post them on here for you.
The names of the Campgrounds are Lake Campalot and the other is Miller's Campground both located in Percy, Illinois. You could try Kaskaskia Motel in Baldwin, Illinois the owner is Mike Turner and he has built on a campground to his property. Good Luck.