Alpine rocks from a mountainous country (6)
I believe the answer is:
nepali
'from a mountainous country' is the definition.
(Nepal is a mountainous country)
'alpine rocks' is the wordplay.
'rocks' indicates anagramming the letters.
'alpine' anagrammed gives 'NEPALI'.
(Other definitions for nepali that I've seen before include "Native of one Himalayan state" , "Language of Kathmandu" , "Foreigner" , "Mountain-dweller" , "one found in mountainous region" .)