Eastern Karakoram Range is actually the huge range forming the geographical partition between India and Central Asia. This range of the Himalaya Mountains includes several high peaks comprising - Teram Kargri, Saltoro Kangri and Rimo. The Karakoram Pass was the major trading link between the markets of Yarkand, Kashgar and Leh. Presently, this region is considered closed to the trekkers. However, only a few mountaineering groups were given the permission to climb. This range offers ample scope for exploration as well as climbing. The Eastern Karakoram Range comprises the Siachen Muztagh, the Rimo Muztagh and the Saser Muztagh - all being sub-groups of the Great Karakoram range. Muztagh is a name given to almost all great snow-capped mountains by the Turki traders. The Muztaghs or the sections of the Karakoram Range are identified by the long glaciers which drain the mountain groups and each of them includes several satellites.
Due to the altitude and severity of the Karakoram Range it is comparatively less inhabited than other parts of the Himalaya Mountains. In the early 19th century, the European explorers first visited it and it was followed by British surveyors. Siachen Muztagh has had a fairly long and varied record of exploration, dating back to 1821 when W. Moor passed near the snout of the glacier and first reported its existence. G. T. Vigne attempted to reach the Bilafond la in the year 1835 from the west. H. Strachey was the first actually to step on to the Siachen glacier in the year 1848. Dr Longstaff, along with Dr A. Neve and Lt Slingsby, were the first ones to traverse the length and breadth of the Siachen glacier.
An Italian expedition led by the Duke of Spoleto in the year 1929 explored a considerable area of the eastern Karakoram Range. The years 1929 and 1930 saw Dr Ph. C. Visser and his wife make their third journey of exploration to the Karakoram. Major M. L. A. Gompertz, who in 1926 had surveyed the Mamostong glacier, suspected the existence of a large unknown glacier system which flowed into the Nubra. Also in the year 1930 Professor Giotto Dainelli entered the Siachen in June. This last exploration completed the survey of the Siachen in its major aspects. Rimo Muztagh has had relatively few visitors and has been explored mainly by expeditions to the Siachen and adjacent areas. One of the largest and most comprehensive scientific expeditions before the First World War was that of the Italian, Filippo de Filippi, during 1914. Saser Muztagh was first explored by Arthur Neve in the year 1899 followed by Longstaff in 1909 and Visser in 1922 and 1935 respectively. The main exploration was carried out by J. O. M. Roberts in the year 1946 when all the Saser peaks and their surrounding areas were covered. Serious climbing activity in this part of the Eastern Karakoram Range started with Prof G. O. Dyhrenfurth`s international expedition of 1934.
One can approach the Saser Kangri group from the Nubra valley to its west or from the turbulent Shyok to its east. The main summit, Saser I (7672 m), eventually allowed its first ascent from the long and arduous passage up the Shyok and from its eastern edge. This was the highest first ascent by an Indian team to date. Meanwhile in the year 1985 an Indo-Japanese expedition approached Saser Kangri II West (7518 m), by the Nubra valley making its ascent by the northwest ridge. A year later Saser III (7495 m) was climbed for the first time by its eastern edge.
The Rimo and Terong peaks form one of the most interesting climbing arenas in the Eastern Karakoram. Rimo IV (7169 m) was the first of the Rimo group to be climbed, in the year 1984 by the Indian Army (K. S. Sooch) who approached the massif from the east (Shyok valley and the Depsang plains). The first ascent of Rimo I was made by an Indo-Japanese team (Hukam Singh), during July/August of 1988. The first ascents of Teram Kangri I (7462 m) and Teram II (7407 m) were made by the Japanese in the year 1975 by the southwest ridge of Teram Kangri II, over its summit and continuing up to the main peak. Teram Kangri II was climbed for the second time in the year 1978 by the Indian Army (Col N. Kumar). Teram Kangri III (7382 m) was climbed by a Japanese team in the year 1979.
The Apsarasas, lying further east and up the Teram Shehr glacier, are really a continuation of the Teram chain. The first ascent of Apsarasas I (7245 m) was by the Japanese in the year 1976. Towards the eastern bank of the Siachen in the north lies the Singhi group, containing the cirque that comprises the Turkestan la with the Sia Kangri group forming the western bank of the glacier. The single ascent of Singhi Kangri (7751 m) was made by the Japanese in 1976. The Sia group lies at the junction of the Siachen and the Abruzzi glacier (an offshoot of the famous Baltoro). The Sia la and the Conway Saddle separate the two mighty glacier systems.
Below the Sia group, in the northwestern corner of the Siachen, there is the Kondus group comprising the Silver Throne (6900 m), Ghent (7401 m) with its northeast peak (7343 m) and its northern outlier Depak (7150 m). Here again all the ascents in this group have been via the Kondus glacier. Directly below the Kondus group and slightly off the main Siachen glacier lies the Saltoro massif, comprising Sherpi Kangri (7380 m), Saltoro Kangri (7742 m) and Saltoro II (7705 m).
Eastern Karakoram Range is regarded as a highly sensitive area and here majority of expeditions are either of the Armed Forces or jointly sponsored by the I.M.F. and foreign clubs.