Tripura, Mizoram, Assam, Arunachal Pradesh, Manipur and Nagaland. They also occur in the Chittagong Hill Tracts. In northern Burma, they occur in the Kachin State, and in adjacent Yunnan are found only in the Trung () and Salween River basins. The role of the mithun is central to the lives of many residents of these areas, including transhumant ones who pair mithun management with sago palm harvesting: In Nagaland, the animals are kept semi-wild, and live in herds, being watched over by special caretakers assigned by the villages or the owner of the herd. They respond to a horn kept specially for the individual caretaker or actual owner to call them. From birth until the time of butchering or market, the Mithun remain in the herd, and roam mostly freely throughout the forests. In culture To the Idu Mishmi, Nyishi people or Adi people (Bangni-Booker Lhobas incl pasi, padam, minyong, Galong now Galo), the possession of gayal is the traditional measure of a family's wealth. Gayal are not milked or put to work but given supplementary care while grazing in the woods, until they are ritually slaughtered or killed for local consumption. Mithuns are wild and each family has a very indigenous marking as a cut on the ear. The gayal is the state animal of Arunachal Pradesh and Nagaland. Gayals play an important role in the social life of the people in Arunachal Pradesh. Marriages are not fixed until the bridegroom's family gives at least one gayal to the bride's household. Gayals are left in the forest, where they usually stay within a small perimeter. Females are usually aggressive when with calves, and there are instances known when people have been severely injured after being gored by one. Males are usually more docile. In Mizoram and Manipur, it is called Sial, Siel, Se/Sia amongst the tribes of the Chin-Kuki-Mizo. It is the most essential and valuable commodity; the wealth of a person is often counted by the number of gayals. It is the sole animal used for sacrificial purposes and feast of merit. The tribes regard a human to be honourable if and when he holds a community feast of one or more gayal on one or more occasions. National Research Centre on Mithun The National Research Centre on Mithun was established at Medziphema in the Chümoukedima District of Nagaland under the Indian Council of Agricultural Research. The mandate