IFT - I agree - last September I was a passenger on such a Papillon Ec-130 flight and I could clearly see five to eight helicopters in the 'Queue' of traffic making its way over the reservoirs and valley route from Boulder City - the higher route apparently. I did not see any helicopters lower than us but I was not looking for them. In my uneducated view, there was about a half-mile separation between us.