The instructions explain that, so it shouldn't interfere with the decision making, but the thing that the instructions don't talk about is whether the park extends indefinitely into the sky. One need not even consider the legal aspect of this (airspace rights: historical versus modern) but merely consider what it means to be in the park! Personally, I think that if the vehicle is making contact with the ground then it's "in" the park, but if it's not making contact with the ground then it's "above" the park.