I-40 meteor crater: There is a gas station right off the highway, stop there and have them call ahead. The gas station is owned by the same people that own the crater. If the RV lot is not full you will have no problems.
Wright-Patterson: There is an empty parking lot near the driveway into the place( recommend parking there). If you enter the driveway make a right at the stop sign. They have a very small sign that is easy to miss.
Anyone every try the strategic air museum just west of Omaha?
In Central Pennsylvania on US 322 westbound, a few miles north of Milroy, are hiking trails accessible to a primitive rest area at the top of the pass. I think it's called Seven Mountain Pass. Great place to get out and stretch the legs, breathe some fresh air, and the view from the overlook is impressive.