Sounds like it could be either Cape Romanzof or Cape Newenham. Both are Long Range Radar Sites and both are, for all practical intents and purposes, considered one way in and one way out.
They're both located in boxed valleys and slope steeply uphill towards the end of the valley.
The NDB approaches dump you off about 4 miles from the threshold, then you fly visually to the runway. The note you're refering to points out the fact that if you need to go around at some point after leaving the MAP you're going to be so far into the valley that you probably won't be able to turn around
and/or outclimb the terrain. You are committed.
These are mostly "Herc strips" but a local freight outfit, Northern Air Cargo, will operate a DC-6 in there. Other than that it's pretty much 207, Caravan or Conquest traffic.
Did you fly in western Alaska? Looks like you're a Canadian?
