Depending on where you are starting from in PA, consider dropping South to I-68 and I-64 to Saint Louis. They are usually in much better condition than I-70 and less traffic. West of Saint Louis we use US-36 or US-50. Both are good highways with interesting small towns to visit along the way. Both have enough campgrounds. RV parks along the way. Several small towns have city parks that allow overnights and some even have hookups. There are also county parks and fairgrounds that have facilities for overnight stops.