The OP just needs to keep in mind who the parks customer would be. They ARE NOT going to get any overnight visitors looking for a quick easy stop while traveling from point A to point B along an Interstate highway. 20-40 miles farther or shorter and you will find an RV park within a mile or 2 of the Interstate.
As a destination I suspect that any RV park has done their due diligence to discover if there is any reason an RVer would be interested in visiting the attractions in the area. If you are interested in only overnighters without the expectation of a few days stay, 8 miles from the Interstate is NOT going to work.