living in the mountains; mountain life
Refers to the act or state of residing in a mountainous area, often with a nuance of a simple or secluded lifestyle.
I left the city and started living in the mountains.
mountain dweller; person living in the mountains
Refers to a person who lives in the mountains, often implying a rustic or self-sufficient lifestyle.
He is a mountain dweller, born and raised.
Compound of 山 (yama, 'mountain') and 住み (sumi, the continuative form of 住む sumu, 'to live').