Complex sentence: The Jungle is not designed to accommodate a large number of RV'ers or vandwellers, and you should be prepared for "boondocking" (self-contained off-road RV camping) if you bring an RV or camper van to the NHC.
Split into simpler sentences: The Jungle is not an RV park and is not designed to accommodate a large number of RVs or camper vans. You should be prepared for "boondocking" (self-contained off-road RV camping) if you bring an RV or camper van to the NHC.