The range is about 500 km (311 mi) in length, and is the most heavily glaciated part of the world outside the polar regions. The Siachen Glacier at 76 kilometres (47 mi) and the Biafo Glacier at 63 kilometres (39 mi) rank as the world's second and third longest glaciers outside the polar regions.
The Karakoram is bounded on the east by the Aksai Chin plateau, on the northeast by the edge of the Tibetan Plateau, and on the north by the river valleys of the Yarkand and Karakash rivers beyond which lie the Kunlun Mountains. At the northwest corner are the Pamir Mountains. The southern boundary of the Karakoram is formed, west to east, by the Gilgit, Indus, and Shyok rivers, which separate the range from the northwestern end of the Himalaya range proper. These rivers flow northwest before making an abrupt turn southwestward towards the plains of Pakistan. Roughly in the middle of the Karakoram range is the Karakoram Pass, which was part of a historic trade route between Ladakh and Yarkand but now inactive.
The Tashkurghan National Nature Reserve and the Pamir Wetlands National Nature Reserve in the Karalorun and Pamir mountains have been nominated for inclusion in UNESCO in 2010 by the National Commission of the People's Republic of China for UNESCO and has tentatively been added to the list.
"Karakoram" is a Turkic word referencing the mountains' black gravel, as seen near Pakistan's Biafo Glacier.
Karakoram is a Turkic term meaning black gravel. The Central Asian traders originally applied the name to the Karakoram Pass. Early European travellers, including William Moorcroft and George Hayward, started using the term for the range of mountains west of the pass, although they also used the term Muztagh (meaning, "Ice Mountain") for the range now known as Karakoram. Later terminology was influenced by the Survey of India, whose surveyor Thomas Montgomerie in the 1850s gave the labels K1 to K6 (K for Karakoram) to six high mountains visible from his station at Mount Haramukh in Kashmir.
In ancient Sanskrit texts (Puranas), the name Krishnagiri (black mountains) was used to describe the range.
Due to its altitude and ruggedness, the Karakoram is much less inhabited than parts of the Himalayas further east. European explorers first visited early in the 19th century, followed by British surveyors starting in 1856.
Floral surveys were carried out in the Shyok River catchment and from Panamik to Turtuk village by Chandra Prakash Kala during 1999 and 2000.
Geology and glaciers
The Karakoram is in one of the world's most geologically active areas, at the plate boundary between the Indo-Australian plate and the Eurasian plate.
A significant part, 28-50% of the Karakoram Range covering an area of more than 15000 km^2 area  is glaciated, compared to the Himalaya (8-12%) and Alps (2.2%). Mountain glaciers may serve as an indicator of climate change, advancing and receding with long-term changes in temperature and precipitation. The Karakoram glaciers are slightly retreating, unlike the Himalayas where glaciers are losing mass at significantly higher rate, many Karakoram glaciers are covered in a layer of rubble which insulates the ice from the warmth of the sun. Where there is no such insulation, the rate of retreat is high.
While the current valley glaciers in the Karakoram reach a maximum length of 76 kilometres (47 mi), several of the ice-age valley glacier branches and main valley glaciers, had lengths up to 700 kilometres (430 mi). During the Ice Age, the glacier snowline was about 1,300 metres (4,300 ft) lower than today.
The naming and division of the various subranges of the Karakoram is not universally agreed upon. However, the following is a list of the most important subranges, following Jerzy Wala. The ranges are listed roughly west to east.
The Khunjerab Pass is the only motorable pass across the range. The Shimshal Pass (which does not cross an international border) is the only other pass still in regular use.
The Karakoram mountain range has been referred to in a number of novels and movies. Rudyard Kipling refers to the Karakoram mountain range in his novel Kim, which was first published in 1900. Marcel Ichac made a film titled Karakoram, chronicling a French expedition to the range in 1936. The film won the Silver Lion at the Venice Film Festival of 1937. Greg Mortenson details the Karakoram, and specifically K2 and the Balti, extensively in his book Three Cups of Tea, about his quest to build schools for children in the region. In the Gatchaman TV series, the Karakoram range houses Galactor's headquarters. K2 Kahani (The K2 Story) by Mustansar Hussain Tarar describes his experiences at K2 base camp.
^Tajikistan's Fedchenko Glacier is 77 kilometres (48 mi) long. Baltoro and Batura Glaciers in the Karakoram are 57 kilometres (35 mi) long, as is Bruggen or Pio XI Glacier in southern Chile. Measurements are from recent imagery, generally supplemented with Russian 1:200,000 scale topographic mapping as well as Jerzy Wala,Orographical Sketch Map: Karakoram: Sheets 1 & 2, Swiss Foundation for Alpine Research, Zurich, 1990.
^French, Patrick. (1994). Younghusband: The Last Great Imperial Adventurer, pp. 53, 56-60. HarperCollinsPublishers, London. Reprint (1995): Flamingo. London. ISBN0-00-637601-0.
^Kala, Chandra Prakash (2005). "Indigenous Uses, Population Density, and Conservation of Threatened Medicinal Plants in Protected Areas of the Indian Himalayas". Conservation Biology. 19 (2): 368–378. doi:10.1111/j.1523-1739.2005.00602.x.
^Searle, Michael P., Geological evolution of the Karakoram Ranges, Ital.J.Geosci, (Boll.Soc.Geo.It.), Vol. 130, No. 2 (2011), pp. 147-159, 5 figs. (DOI: 10.3301/IJG.2011.08)
^Muhammad, S., Tian, L. and Khan, A. (2019) ‘Early twenty-first century glacier mass losses in the Indus Basin constrained by density assumptions’, Journal of Hydrology, 574, pp. 467–475. doi: [doi.org].
^Gansser (1975). Geology of the Himalayas. London: Interscience Publishers.
^Muhammad, S. and Tian, L. (2016) ‘Changes in the ablation zones of glaciers in the western Himalaya and the Karakoram between 1972 and 2015’, Remote Sensing of Environment. Elsevier Inc., 187, pp. 505–512. doi: 10.1016/j.rse.2016.10.034.
^MUHAMMAD, S., TIAN, L., & NÜSSER, M. (2019). No significant mass loss in the glaciers of Astore Basin (North-Western Himalaya), between 1999 and 2016. Journal of Glaciology, 65(250), 270-278. doi:10.1017/jog.2019.5
^Veettil, B.K. (2012). "A Remote sensing approach for monitoring debris-covered glaciers in the high altitude Karakoram Himalayas". International Journal of Geomatics and Geosciences. 2 (3): 833–841.
^ abKuhle, M. (1988). "The Pleistocene Glaciation of Tibet and the Onset of Ice Ages- An Autocycle Hypothesis.Tibet and High Asia. Results of the Sino-German Joint Expeditions (I)". GeoJournal. 17 (4): 581–596. doi:10.1007/BF00209444.
^Kuhle, M. (2006). "The Past Hunza Glacier in Connection with a Pleistocene Karakoram Ice Stream Network during the Last Ice Age (Würm)". In Kreutzmann, H.; Saijid, A. (eds.). Karakoram in Transition. Karachi, Pakistan: Oxford University Press. pp. 24–48.
^ abcKuhle, M. (2011). "The High Glacial (Last Ice Age and Last Glacial Maximum) Ice Cover of High and Central Asia, with a Critical Review of Some Recent OSL and TCN Dates". In Ehlers, J.; Gibbard, P.L.; Hughes, P.D. (eds.). Quaternary Glaciation - Extent and Chronology, A Closer Look. Amsterdam: Elsevier BV. pp. 943–965. (glacier maps downloadable)
^ abKuhle, M. (2001). "Tibet and High Asia (VI): Glaciogeomorphology and Prehistoric Glaciation in the Karakoram and Himalaya". GeoJournal. 54 (1–4): 109–396. doi:10.1023/A:1021307330169.
^Kuhle, M. (1994). "Present and Pleistocene Glaciation on the North-Western Margin of Tibet between the Karakoram Main Ridge and the Tarim Basin Supporting the Evidence of a Pleistocene Inland Glaciation in Tibet. Tibet and High Asia. Results of the Sino-German and Russian-German Joint Expeditions (III)". GeoJournal. Dordrecht, Boston, London: Kluwer. 33 (2/3): 133–272. doi:10.1007/BF00812877.
^Jerzy Wala, Orographical Sketch Map of the Karakoram, Swiss Foundation for Alpine Research, Zurich, 1990.