I've gotta take a little exception to the 2 vehicles 2 fees response. There is zero difference to driving in a 37' Class A with a Toad vs a 37' 5th wheel with a truck..... Once one is parked, it stays parked and becomes your accommodation, while the other becomes your transport. Dinging one for extra fees makes little sense to me.
I see the issue is they don't have a clean mechanism to manage the pricing of the toad/RV when their current pricing model is "vehicle" based.
And having spent over a decade running an eco-adventure resort and sitting on the board of directors of a number of provincial tourism boards it does not surprise me to see governments being penny wise and dollar poor when it comes to promoting toursim in their areas. Grab the money for the gov rather than making the region attractive as a whole and bringing more tourism revenue into the economy as a whole is not an uncommon story. What folks spend on accomodations in the parks is peanuts compared to all the other things they drop money on while in the area.
Still a poor strategy to me, at least make it really clear on your websites, I watched two other couples leave the check-in pissed about the extra fees just in the short time I was there. Multiply that over all the parks and a whole season and thats a whole lot of negative advertising for the state....
Wisonsin, here I come!!!