There were a lot of motor homes there when I was there. They looked to be accommidating for trailers as well.
I am not sure of how many spaces are available but they may have tractor trailer parking which should fit a motor home towing a small vehicle (?). You can't park overnight though if that's what you were thinking. All in all I would suggest you call to be sure if you are planning on going.
Hershey has a huge parking lot, I'm not sure why you would tow a motorhome, but there is plenty of space for buses and such. You cannot park there overnight.
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