Changlang District, showered with Bio-diversity is the eastern most part of India, having international boundary with Myanmar (Burma), where the morning Sun light first touches the Horizon of the eastern Mountain ranges of the district while the rest of the Country still napping in their cozy beds waiting for the emergence of the dawn of the day.
Changlang District covered with picturesque hills lies in the southeastern corner of Arunachal Pradesh, northeast India. It has an area of 4662 sqr. Km and a population of 1,25,334 persons as per 2001 Census. According to legend the name Changlang owes its origin to the local word CHANGLANGKAN which means a hilltop where people discovered the poisonous herb, which is used for poisoning fish in the river.
Changlang District has reached the stage in its present set up through a gradual development of Administration. Prior to 14th November 1987, it was a part of Tirap District. Under the Arunachal Pradesh Reorganization of Districts Amendment Bill, 1987,the Government of Arunachal Pradesh, formally declared the area as a new District on 14th November 1987 and became 10th district of Arunachal Pradesh.
The District lies between the Latitudes 26°40'N and 27°40'N, and Longitudes 95°11'E and 97°11'E .It is bounded by Tinsukia District of Assam and Lohit District of Arunachal Pradesh in the north, by Tirap District in the west and by Myanmar in the south-east.
Except Miao, Diyun, Bordumsa and Kharsang circles and a few narrow strips of flat land in some parts of Changlang, Jairampur, Vijoynagar, Nampong and Namtok circles, the whole district is hilly area. The hills ranging from 200 to 4500 metre in height generally slopes down towards northwest. The highest peak in the district is Daphabum (4500 metre) above sea level.
The aboriginal inhabitants of Changlang District are the Tangsas, Singphos and Tutsas. The Tangsa tribe is comprise of a number of Sub-Tribes, namely Muklom, Havi, Longchang, Mossang, Jugli, Kimsing, Ronrang, Mungrey, Longphi, Longri, Ponthai, Sangwal, Tikhak, Yungkuk, Sakieng and Thamphang. They occupy the southeastern hills of the district along Indo-Myanmar border and Namchik basin.
The Singphos occupy the plain foothills area of northern part of the district under Miao, Bordumsa and Diyun circles. The Tutsas live in the western part of the district under Changlang and Khimiyong circles. Other tribes who have migrated to the district are Noctes (APST), Lisus (Yobin), and Deoris. The Tibetans, Chakmas and Hajongs came as refugees.
The Namdapha Tiger reserve is located in this district.