This was either one very busy helicopter pilot, or there were two yellow helicopters that would take turns flying over the Falls. As we had stopped on our road trip before passing over in to Canada, we walked around a bit, enjoying the warm summer weather, the Falls themselves (quite impressive), and people watching. I did notice this yellow helicopter flying over the city and the Falls themselves – but only one. Perhaps for safety reasons there is only one helicopter than can fly in that zone, understandably. But the pilot must have been tired by the end of the day!