Qin Mountains, mountain range in north China, extending along a west-east axis from southeastern Gansu province into Shaanxi and Henan provinces. Considered to be an eastern extension of the Kunlun Mountains, it constitutes a watershed between the Wei River to the north and Han River to the south and reaches a height of 12,359 feet (3,767 metres) at Mount Taibai. The range forms a sharp physical divide, both climatic and topographic, separating the monsoon subtropical zone of green, forested hills in the south from the warm-temperate zone of dry loess lands in the north. This division extends eastward along the Dabie Mountains and Huai River in Anhui province.