Geographically and culturally part of Central Asia, this region includes western Gansu, Xinjiang, Ningxai and part of Inner Mongolia.
The topography is highly varied and includes large stretches of arid desert and wasteland, fertile oasis, grassy plateaus and high mountain ranges. The Altai range rises to more than 4,000 meters above sea level and the Tianshan to 7,435.
The climate is generally dry, averaging only 10 centimeters of rain yearly in some areas. The region is China's main source of sheep, cattle, horses and camels. Some areas are suited to grain and cotton production.
Population is sparse in the grassland and in mountain pastureland, in many places less than one person per square kilometer. There are relatively few cities, the largest are Urumqi and Kashgar, which were stages on the old Silk Road.
A large percentage of the population belong to minority nationalities, such as Uigars, Hui, Kazak, Kirgiz, Mongols, Tajiks and others. In Xinjiang over half of the population belongs to Turkic-speaking minority groups, and almost one-third of Ningxia's population are Hui. Because of heavy Han immigration, Mongols are now no more than 15 percent of the population of the Inner Mongolian Autinomous Region.