The people of Thimphu valley in western Bhutan speak Ngalongkha or Dzongkha with marked difference from other speakers. The speakers of this dialect moves to the Punakha valley in the winter. Beside accents, there are also language features in Shar dialect which are distinct from other dialects. Ngalongkha is the native language of the western valleys of Bhutan extending from Pelela pass to Haa Valley. It has many dialects and belongs to the Central Bodish group according to the leading linguists working on Bhutan. Since the state administration of Bhutan was based in the western region from the 17th to the 20th century, the language became the medium of official administration.