X2 on wadcutter advice about taking I-255. Look up Grafton, IL tourism, Aerie's winery website, the drive south from Grafton to Alton is beautiful. If you have a truck, toad or very small rv take a drive through Elsah, Il it is just south of Grafton. Historic village tucked in the bluff. I don't think Pere Marquette SP campground is on Reserve America. Electric, fill your water tank. The lodge is very nice, rustic. There is a nice museum by the Alton lock and dam, further in Hartford there is a tall observation tower where the Missouri and Mississippi river meet. Down the road is the Lewis & Clark State Historic site.
Safe travels, Marcia