People have been searching for a lost Dragonfly in the South Island of NZ for decades, we're far smaller (and so was the plane, to be fair) than Alaska! It's a 2.5 hours drive from my town by the Pacific Ocean over the Alps to a wild beach on the Tasman Sea. There's a one day running/cycling/kayaking endurance race from the Tasman coast over a pass in the Southern Alps, down to the Pacific coast. (Guess what it's called)

And the search area(s) is/are reasonably well known now - it was flying to Milford Sound, there were several mountain passes feasible for flying over the Main Divide in a rather underpowered aircraft to get there, and there were some statements from locals in the high country in the east who believe they heard the plane as it flew into the mountains that yielded places to look.

There's a general agreement forming about which area it crashed, but no evidence yet. Makes for good practice in extreme terrain for LandSAR exercises though.

So yeah, far smaller search area, still missing. Google ZK-AFB for more, there's a few books on it, one gent in particular has been searching most of his adult life for it.