Gansu lies between the Tibetan Plateau and the Loess Plateau, bordering Mongolia (Govi-Altai Province) to the northwest, Inner Mongolia and Ningxia to the north, Shaanxi to the east, Sichuan to the south, and Xinjiang to the west. The Yellow River passes through the southern part of the province. The province contains the geographical centre of China, marked by the Center of the Country Monument at . Part of the Gobi Desert is located in Gansu, as well as small parts of the Badain Jaran Desert and the Tengger Desert. The Yellow River gets most of its water from Gansu, flowing straight
Gobi Desert been the bottom of a former lake, but is now nearly a dry salt-basin. The surface configuration is in fact markedly similar to that which occurs in the inter-mount latitudinal valleys of the Kunlun Mountains. The hydrography of the Ghashiun-Gobi and the Kuruk-tagh is determined by these chequered arrangements of the latitudinal valleys. Most of the principal streams, instead of flowing straight down these valleys, cross them diagonally and only turn west after they have cut their way through one or more of the transverse barrier ranges. To the highest range on the great swelling Grumm-Grzhimailo gives the name of