I live in WV & would like to take a family vacation by flying to Portland then driving to South Dakota?

Most RV campgrounds have showers. I know KOA does. Call a couple of R V rental companies and ASK prices or the size and time you want. Need to do that right away as it may be difficult to get a reservation this late. Or, you can rent a car, or SUV and use campgrounds insted of hotels if you have a tent and quipment and like to camp.