we always stayed at the four -h park just north of rockville you will get electric they have 20 and 30 amp services and they have a dump station seems like it is fairly cheap per night like $20 per night they do on a first come first serve basis Most campgrounds are booked by know for the festivel so here is a second option I don't think they have ever turned anybody away. They handle anything from motorhomes to tents.
scott