The RV parks near major attractions in the west are nothing like the parks in the northeast. You won't find party campgrounds. The locals have no need to get away from the city and blow off steam. Instead the parks will be full of tourists who spend all day at the attractions and return to clean up, eat, sleep and recover to do it all again. The parks themselves are not the attraction. Nobody stays in the park day in, day out using the park as their entertainment. Some of the parks may have a pool, a playground or another time waster like mini-golf, but that is about it.
Near places like Mount Rushmore, land is extremely expensive and scarce. Those real estate prices combined with the lack of land makes it imperative for those RV parks to maximize their revenues in order to make a profit, so you aren't going to find 1/2 acre sites. I think you will find you will ultimately care much less about the RV parks on this trip than you do at home. They are going to serve a different purpose.
