Here is a super hard one. If no one gets it in a day, I'll reveal it. It is in the Pine Barrens, right next to a road. Each shot is the wall opposite the other.
That opening is where a lot of horse trailers were parked. Look at the 2007 aerial. Maybe that had something to do with it. Maybe they used it to support the trailer hitch and forgot it.
That looks to be very close to the spot they eventually put a cable and gondola across the river for tourists.
http://www.niagaraparks.com/niagara-falls-attractions/whirlpool-aero-car.html
In fact, he may have even taken it from the gondola.