Golmud is part of Haixi Prefecture in western Qinghai Province. Despite being nominally a "city", the built-up urban area of Golmud comprises only of the county's . Most of the county lies in the southern Qaidam Basin and in the foothills of the Kunlun Mountains. A large southern exclave is administered as the "town" of Tanggula, separated from the rest of the county by the western panhandle of the Yushu Tibetan Autonomous Prefecture. The northern part borders Xinjiang to its northeast; the southern exclave borders the Tibetan Autonomous Region to its southwest.