State Park wedding

I was wondering if anyone has done a wedding in a state park here in Indiana. If I have to do the big ceremony (I'm hoping for a courthouse ceremony because I don't people very well, but that's not going in my favor), I was thinking of seeing if a state park in Southern Indiana would allow me to have it there. Somewhere in the Hoosier National Forest would be ideal if possible (I live in Tell City, I am literally surrounded by this forest). But for those of you who went this route, how much did it cost? Were there any restrictions to doing a wedding in a state park?