In the trailer for Elevation, aliens have trouble hunting humans in hard-to-reach places, which is why humanity has gathered in the Rocky Mountains. You can place your bets now as to how likely "Rocky Mountain High" is in the soundtrack! reactormag.com/elevation-tr...

Elevation Trailer Sees Anthony Mackie Battling Sea-Level Loving Monsters - Reactor

They don't like to be high up

Or "Ain't No Mountain High Enough "

I'm starting to like these movies with monsters with gimmicky limitations. They can only attack humans who make sound, only can harm humans that see them. Only cold blooded animals mutated into kaiju.