Yup, mountain waves are naughty. We have some bad places in our country as well, so some aircraft have been smacked into a glacier. Then there is visibility.
Same story with Greenland, where you just have mountains rising steeply some 10K from the sea.
I recall a DC-4 pilot who almost ened his days there (visibility issue), but got our by a hair's width by forcing the aircraft into a hammerhead. With passengers and all. Well, he was an old fighter jock....