Nearly missed your evac question. If you can afford it, as Bellerphon pointed out, the first light helicopters exist. You don't really hear about them being used in Korea outside of MASH, but they exist. Chances are that a surplus jeep or deuce and a half is going to be your evacuation platform of choice. There are specialized ambulances, but getting up the nearest trail with some morphine and life saving equipment on board is going to matter more than having the best option that is stuck on the gravel two miles away.