Meramac state park in Sullivan, maybe an hour west of SL. State park rates with water/ele. is around $21. large campground, but most of the weekend crowd has most likely left so there should be spots there....close to a river, lots of shade.
A friend of mine is a campground host there.....probably the only 13 foot scamp
in the park....site 101 or thereabouts. if you are past there, there is another one on down the road maybe 45 minutes away...Ogandan or something state park.....has a nice cavern there. have fun. Sorry i am late to responding to your inquiry, but had lots of things to do today on the farm.