Qilian Mountains

39°12′N 98°32′E / 39.200°N 98.533°E / 39.200; 98.533

The Qilian Mountains, along with the Altyn-Tagh sometimes known as the Nan Shan as it is to the south of the Hexi Corridor, are northern outliers of the Kunlun Mountains, forming the border between the Qinghai and Gansu provinces of China.

The range stretches from the south of Dunhuang some 800 km to the southeast, forming the northeastern escarpment of the Tibetan Plateau and the southwestern border of the Hexi Corridor.

The eponymous Qilian Shan peak, situated some 60 km south of Jiuquan, at 39°12′N 98°32′E / 39.200°N 98.533°E / 39.200; 98.533, rises to 5,547 m. It is the highest peak of the main range, but there are two higher peaks further south, Kangze'gyai at 38°30′N 97°43′E / 38.500°N 97.717°E / 38.500; 97.717 with 5,808 m and Qaidam Shan peak at 38°2′N 95°19′E / 38.033°N 95.317°E / 38.033; 95.317 with 5,759 m. Other major peaks include Gangshiqia Peak in the east.

The Nan-Shan range continues to the west as Yema Shan (5,250 m) and Altun Shan (Altyn Tagh) (5,798 m). To the east, it passes north of Qinghai Lake, terminating as Daban Shan and Xinglong Shan near Lanzhou, with Maoma Shan peak (4,070 m) as an eastern outlier. Sections of the Ming dynasty's Great Wall pass along its northern slopes, and south of the northern outlier Longshou Shan (3,616 m).

The Qilian mountains are the source of numerous, mostly small, rivers and creeks that flow northeast, enabling irrigated agriculture in the Hexi Corridor (Gansu Corridor) communities, and eventually disappearing in the Alashan Desert. The best known of these streams is the Ejin (Heihe) River. The region has many glaciers, the largest of which is the Touming Mengke. These glaciers have undergone acceleration in their melting in recent decades.

Lake Hala is a large brackish lake, located within the Qilian mountains.

The characteristic ecosystem of the Qilian Mountains has been described by the World Wildlife Fund as the Qilian Mountains conifer forests.