Physical map of Inner Mongolia, China
Officially Inner Mongolia is classified as one of the provincial-level divisions of North China, but its great stretch means that physically parts of it belong to Northeast China and Northwest China as well. It borders eight provincial-level divisions in all three of the aforementioned regions (Heilongjiang, Jilin, Liaoning, Hebei, Shanxi, Shaanxi, Ningxia, and Gansu), tying with Shaanxi for the greatest number of bordering provincial-level divisions. Most of its international border is with Mongolia, which, in Chinese, is sometimes called "Outer Mongolia", while a small portion is with Russia's Zabaykalsky Krai.
Inner Mongolia largely consists of the northern side of the North China Craton, a tilted and sedimented Precambrian block. In the extreme southwest is the edge of the Tibetan Plateau where the autonomous region’s highest peak, Main Peak in the Helan Mountains reaches 3,556 metres, and is still being pushed up today in short bursts. Most of Inner Mongolia is a plateau averaging around 1,200 metres in altitude and covered by extensive loess and sand deposits. The northern part consists of the Mesozoic era Khingan Mountains, and is owing to the cooler climate more forested, chiefly with Manchurian elm, ash, birch, Mongolian oak and a number of pine and spruce species. Where discontinuous permafrost is present north of Hailar District, forests are almost exclusively coniferous. In the south the natural vegetation is grassland in the east and very sparse in the arid west, and grazing is the dominant economic activity.
Owing to the ancient, weathered rocks lying under its deep sedimentary cover, Inner Mongolia is a major mining district, possessing large reserves of coal, iron ore and rare-earth minerals, which have made it a major industrial region today.