West Siang, located in the state of Arunachal Pradesh is an administrative district in the state. It is majorly populated by the Adi tribe which includes a large number of Aboriginal groups and subgroups such as the Shimongs, Milangs, Pasis, Karkos, Pangis, Minyongs, Padams, Ashings, Tangmas and Boris. The Adis are related to the Astro- Mongoloid race, and are good looking, strong and dynamic.
The territory was moved from West Siang district to East Siang district in 1989. After a decade, the district was partitioned to make Upper Siang district in 1999. The district got its name from the River Siang which originates from Tibet, where it is called Tsangpo. It passes through the entire area and descents down into the plains of Assam and becomes Brahmaputra.