Mongolia is also a mountainous country. Its topography consists of mountains, hummocks and high denudation plains, forming three major regional stages on its surface. Erosive mountain relief and depressions of tectonic origin formed during the late Cretaceous and Early Quaternary periods are numerous in the northern regions of the country. Erosion, tectonic, depression and hump of folded mountains, lifted during the Cretaceous period's fourth stage, occur frequently. Eighty per cent of all Mongolian territory is situated about 1,000 meters above sea -level. The surface of Mongolia comprises the biggest parts of the Mongol Altai Mountains, Great Lakes Depression, mountains surrounding Lake Khuvsgul, the Khangai mountain range, Orkhon-Selenge river basin, Khentii Mountain, Dornod Steppe and Great Khyangan mountain eastwards.
The Mongol Altai Mountains are situated in the western part of Mongolia stretching for 600-650 kilometres and were structured by thin hills, hollows and straight precipitous crags, which have a height of more than 4,000 meters. There is the Khuiten peak of the Altai Tavan Bogd Mountain, which is the highest point of Mongolia. The peak is 4,374 meters above-sea-level. There are glaciers in the highest parts of the Mongol Altai, and the humps and hollows of the ice-age period were kept open in Khuvsgul, Khangai, Khentii and Altai Mountains. The Great Lakes Depression is situated in the eastern part of the Mongol Altai and consisted of a few hollows with bigger lakes. The Mountains surrounding Khuvsgul are analogous with Lake Baykal by their origin. The mountains were formed along cracks between mountains and created by lakes, which are situated along the longitude surroundings of the Khuvsgul and Darkhad Depressions.
Khuvsgul Lake was formed in the Khuvsgul Depression and lake-origin steppe, small lake and river valleys predominate in the Darkhad Depression. The Khuvsgul Mountains are situated on the northern side of the Khangai Mountain range and were formed by Lakes Ulaan Taiga and Khoridol Saridag, 3491 meters above sea level. A zone, which is along the southward latitude, separates the Khuvsgul Mountains. Rivers of the Tes basin and the River Delger of the Selenge basin flow from the zone to the west and east. This zone was named the " 1905 splitting zone" after having a strong earthquake along the zone in 1905. A wide range of the Khangai Mountains is situated in the Centre of Mongolia. From the zone, the Bulnai, Tarvagatai and Buren mountain ranges continue from the Khangai range and the Khangai Mountain is included in the splitting zone.
The highest peak of the Khangai Mountain range is the Otgontenger Mountain, which is situated in the western part of the mountain range and is 4021 meters above sea level. There is a little glacier on the top of the Otgontenger. There are waterfalls in the rivers with their source from the Khangai Mountain range. So the valley of the rivers is rich in rapids and waterfalls, which occur frequently. The Ulaan Tsutgalan Waterfall on the River Orkhon is one of the biggest Waterfalls in Mongolia. The Lakes Valley is situated in the thin depression between the mountains at the southward point of the head of the Khangai mountain range. The mountains of the Gobi-Altai continue 600 kilometres at the southward end of the Lakes Valley and were formed by several separate mountains. The highest point of the Gobi-Altai Mountains is the Great Bogd Mountain, the height of which is 3957 meters.
The state special protected area of the Mongol Altai Mountain is made up of the protected area of Khuch Serkh Mountain and the natural complex of the Altai Tavan Bogd. A wide desert-like depression named Altai Uvur Gobi continues southward of the Gobi-Altai Mountain and it gradually changes to the stony desert zone with dark-coloured desert scraps and stone surface. Mongolian central, southern and Dornod province's wide steppes continue over 1200 kilometres to the east of the head of the Khangai Mountain range, Lakes Valley and Gobi-Altai Mountain. This wide broad steppe gets lower from the west to the east and its absolute height is 560 meters above sea level. The zenith of the Khentii Mountain range is the Asralt Khairkhan Mountain, which is 2800 meters high. The mountains, formed by basalt plateau and granite massif, are located in the basin of River Khalkh-Gol, at the east edge of Mongolia. The valley of the River Khalkh-Gol and its tributary rivers and steppe with fertile brown and black soil are ideal for agricultural and farming and an important eco-systematic reserve area, which is in its relatively original condition.
