It's at Forest Glenn, near Westville , IL. The same park that Octoberfest is held at.
These are some directions from an old Fest thread;
( I'll get more pictures of the turns up when I get this years Fest pictures online. )
Turn East at the CVS in Westville. (Left if you are coming from Danville.) Follow the curving country highway (I think there might be 4 turns ?) until you see the sign for Forest Glen County Preserve. Turn Left into the park. There are a few pictures here;
Octoberfest 2004
Follow signs to the Group Campground. The road is curvy, and there are side roads that are confusing at first. Just try to stay on the main road. There is one fork where the side road you don't want is right in front of you, and the main road is going to the left at a 90 degree angle.
Make a right turn here at this sign. Follow that dirt road untill you see the battlefield.
Anyone care to elaborate ?