Gobi Desert from , and those of the ranges from higher, though in a few cases they reach altitudes of . The elevations do not form continuous chains, but make up a congeries of short ridges and groups rising from a common base and intersected by a labyrinth of ravines, gullies, glens and basins. But the tablelands, built up of the horizontal red deposits of the Han-gai (Obruchev's Gobi formation) which are characteristic of the southern parts of eastern Mongolia, are absent here or occur only in one locality, near the Shara-muren river. They are greatly intersected by gullies or dry watercourses.
Gobi Desert is a rain shadow desert, formed by the Tibetan Plateau blocking precipitation from the Indian Ocean reaching the Gobi territory. The Gobi measures over from southwest to northeast and from north to south. The desert is widest in the west, along the line joining the Lake Bosten and the Lop Nor (87°–89° east). It occupies an arc of land in area as of 2007; it is the fifth-largest desert in the world and Asia's second largest. Much of the Gobi is not sandy but has exposed bare rock. In its broadest definition, the Gobi includes the long stretch of desert