History of Haixi

After 1949, the People’s Government of Dulan County was founded and the area was renamed Dulan Autonomous District (都兰自治区); in 1954, Dulan was renamed Haixi Mongol, Tibetan and Kazakh Autonomous District (海西蒙藏哈萨克族自治区) and in 1955, Haixi Mongol, Tibetan and Kazakh Autonomous Prefecture (海西蒙藏哈萨克族自治州). In 1963, it was renamed “海西蒙古族藏族哈萨克族自治州” (with the “Tibetan” added to the name of official county name). In 1985, after the Kazakhs had returned to Xinjiang, it was again renamed Haixi Mongol and Tibetan Autonomous Prefecture.

Source From: https://en.wikipedia.org/wiki/Haixi_Mongol_and_Tibetan_Autonomous_Prefecture#History