The Yenisei or Yenisey is the fifth-longest river system in the world, and the largest to drain into the Arctic Ocean. Beginning in Mungaragiyn-gol in Mongolia, it follows a northerly course through the Krasnoyarsk Dam before draining into the Yenisei Gulf in the Kara Sea. Its basin comprises Lake Baikal, the world's deepest lake. The Yenisei divides the Western Siberian Plain in the west from the Central Siberian Plateau to the east; it drains a large part of central Siberia. Its delta is formed between the Gyda Peninsula and the Taymyr Peninsula. The Yenisei is the central river of three large Siberian rivers that flow into the Arctic Ocean (the other two being the Ob and the Lena). The maximum depth of the Yenisei is and the average depth is .

Etymology The first written mention of the Yenisei River, as "Kem", dates back to the 7th century in Tang dynasty China, at the time of contact with Yenisei Kyrgyz of this region. The word 令狐徳棻等撰『周書』1971 中華書局; 908.李延壽撰『北史』1974 中華書局; 3286. appears in the Book of Zhou, vol. 50, and the History of the Northern Dynasties, vol. 99, while 宋濂撰『新唐書』1975中華書局; 6148. appears in the New Book of Tang, vol. 217. In addition, 宋濂撰『元史』1976中華書局; 1574. is found in the 14th-century the History of Yuan, vol. 63. These contacts were made by the Chinese as they approached the upper Yenisei River from the south. The characters and have been compared to Käm in Orkhon inscriptionsThomsen V. 1896 Inscriptions de l'Orkhon. la Société de Littérature Finnoise, Helsingfors.: 100, 123, 140. from the 8th century. The term Kem كيم is also found in the 13th‒14th-century Oirat Biography in the Jami' al-Tawarikh.Хетагуров Л. А., Семенов А. А. 1952 Рашид-Ад-Дин Сборник летописей. Том 1-1 // Ленинград : Издательство Академии Наук СССР с. 118.

The etymology of Käm is not believed to be of Turkic origin,Hambis L. 1956 "Notes sur Käm, nom de l'Yenissei supérieur". Journal Asiatique, vol. 244, 281‒300. and although a Samoyed derivation has been proposed,Vásáry I. 1971 "Käm, an Early Samoyed Name of Yenisey", L. Legeti (ed.) Studia Turcica, Budapest: Akademiai Kiado, 469‒482. its precise origins remain unclear.

Today, the word survives only in Sayan Turkic languages: in Tuvan as xem хем, meaning "river",Тенишев Э.Р., Тувинско-русский словарь: около 22 000 слов // Москва : Советская энциклопедия. 1968. с. 473. and in its sister language, Tofa, as hem hем, also meaning "river".Рассадин В. И., Словарь тофаларско-русский и русско-тофаларский // Санкт-Петербург : Дрофа. 2005. с. 55. These languages are considered to have had close contact with those mentioned above in ancient times.Hambis 1956, 282.Vásáry 1971, 475. Additionally, there are just over 50 river names containing the suffix -kem -кем in the Altai Republic,Молчанова О. Т., Топонимический словарь Горного Алтая // Горно-Алтайское отделение Алтайского книжного издательства. 1979. С. 55—62. and the term Kim (Ким) as in Kim suğ (Ким суғ), meaning "Yenisei River" barely exists in Khakas.Чанков Д. И., Русско-хакасский словарь: 31000 слов // Государственное издательство иностранных и национальных словарей. 1961. с. 960. All of these instances are confined to the region in and around the present-day Republic of Tuva.

Meanwhile, in the 17th century, Russians reached the lower part of the Yenisei River from the northwest; along the way, by 1600, the Tobolsk Cossacks built Fort Mangazeya by the Taz River. It is believed that the name of the Yenisei River was transmitted, either directly or indirectly, from Samoyed-speaking peoples in the region with whom the Russians had contact. This contact eventually led to the adoption of the name "Yenisei", with a Russian accent.Müller G. F. 1778 Sammlung rußischer Geschichte des Herrn Collegienraths Müllers in Moscow; S. 517‒518.

Additionally, by the end of the 16th century, the Yenisei River was already known to Dutch navigators, who referred to it as "Gilissi", "Gelissi", or "Geniscea", among other names. Although the exact spelling varied, these are phonetically similar to "Yenisei".Бурыкин А. А. 2011 Енисей и Ангара. К истории и этимологии названий гидронимов и изучению перспектив формирования географических представлений о бассейнах рек Южной Сибири // Новые исследования Тувы. 2011, № 2—3. с. 286. In particular, the modern Dutch pronunciation of "Geniscea" as [xɛnisə] is quite close to "Yenisei". The term "Yenisei" (Енисей) appeared in Russian literature slightly later, around 1600, in the form that is still used today.Бурыкин 2011, с. 282. Unlike in Dutch, the Russian spelling has been relatively stable since the 17th century, with only minor variations such as "Yenisei a" (Енисея) or "Yenisya" (Енися).Русско-китайские отношения в XVII веке. Том 1 1608—1683 // Наука. 1969. с. 594.

The etymology of "Yenisei" remains unclear. Renowned linguist Max Vasmer, for instance, has suggested that the Nganasan word "Jentajea", the Enets "Jeddosi", and the Selkup "N'andesi", all meaning "Yenisei River", might correspond to unidentified Samoyed languages,Vasmer M. J. Этимологический словарь русского языка. Том 1 (А—Д) // М. Прогресс. 1964 [1950—1958]. с. 20. probably quoted Matthias Castrén's vocabulary.Castrén, M. 1855 Wörterverzeichnisse aus den samojedischen Sprachen. S. 52, 83, 141, 238. V. K. Nikonov has proposed that the word could derive from "iondessi" (иондесси), meaning "big river" in Selkup, Khanty, or even Evenki.Никонов В. К., Краткий топонимический словарь. // М. Мысль 1966. с. 136. More recently, some have speculated that "Yenisei" is a compound word of unconfirmed Old Kyrgyz (or inspired by Tuvan language?) ene (эне), meaning "great-grandmother; nanny" + say (сай), meaning "gravel; ford"..

However, the above considerations, except Vasmer's, remain speculative false etymologies, as they do not refer to the reliable modern dictionaries of the respective languages.Бурыкин 2011 С. 280—281. Researchers are encouraged to conduct more detailed studies based on proper contemporary linguistic sources and historical documents.Бурыкин 2011 С. 279—304.

Geography The Yenisei proper is long, measured from the confluence of its source rivers the Great Yenisei and Little Yenisei at Kyzyl to its mouth in the Kara Sea. From the source of its tributary the Selenga, it is long.Енисей, Great Soviet Encyclopedia It has a drainage basin of . The Yenisei flows through the Russian federal subjects Tuva, Khakassia and Krasnoyarsk Krai. The city of Krasnoyarsk is situated far upstream on the Yenisei, and the industrial city of Norilsk is nearby on the Arctic Ocean's Taymyr Peninsula.

Tributaries The largest tributaries of the Yenisei are, from source to mouth:

Little Yenisey (left) Great Yenisey (right) Khemchik (left) Kantegir (left) Abakan (left) Tuba (right) Mana (right) Bazaikha (right) Kacha (left) Kan (right) Angara (right) Kem (left) Bolshoy Pit (right) Sym (left) Dubches (left) Podkamennaya Tunguska (right) Bakhta (right) Yeloguy (left) Nizhnyaya Tunguska (right) Turukhan (left) Kureyka (right) Khantayka (right) Bolshaya Kheta (left) Tanama (left)

Lake Baikal

A significant feature of the Upper Yenisei is Lake Baikal, the deepest and oldest lake in the world.

Brekhovskie Islands The Brekhovskie Islands (Russian-language article: Бреховские острова) lie in the Yenisei estuary and have an area of some 1,400,000 hectares. They provide a wetland habitat for rare and endangered birds and are an internationally important nesting and breeding area for several types of waterfowl. The most north-easterly of the islands, Nosonovskij Ostrov ("Nose Island") was visited by Fridtjof Nansen in 1913.

Flora and fauna The Yenisei basin (excluding Lake Baikal and lakes of the Khantayka headwaters) is home to 55 native fish species, including two endemics: Gobio sibiricus (a gobionine cyprinid) and Thymallus nigrescens (a grayling).Freshwater Ecoregions of the World (2008). Yenisei. Retrieved 16 July 2014. The grayling is restricted to Khövsgöl Nuur and its tributaries. Most fish found in the Yenisei basin are relatively widespread Euro-Siberian or Siberian species, such as northern pike (Esox lucius), common roach (Rutilus rutilus), common dace (Leuciscus leuciscus), Siberian sculpin (Cottus poecilopus), European perch (Perca fluviatilis) and Prussian carp (Carassius gibelio). The basin is also home to many salmonids (trout, whitefish, charr, graylings, taimen and relatives) and the Siberian sturgeon (Acipenser baerii).

The Yenisei valley is habitat for numerous flora and fauna, with Siberian pine and Siberian larch being notable tree species. In prehistoric times Scots pine, Pinus sylvestris, was abundant in the Yenisei valley .Stein, Ruediger et al. 2003. Siberian river run-off in the Kara Sea, Proceedings in Marine Sciences, Elsevier, Amsterdam, 488 pages There are also numerous bird species present in the watershed, including, for example, the hooded crow, Corvus cornix.C. Michael Hogan. 2009. Hooded Crow: Corvus cornix, GlobalTwitcher.com, ed, N. Stromberg

Taimyr reindeer herd The Taimyr herd of tundra reindeer (Rangifer tarandus sibiricus), the largest reindeer herd in the world, migrates to winter grazing ranges along the Yenisei . It had an estimated 800,000-850,000 individuals as of 2010, but has peaked at over one million.

Navigation

River steamers first came to the Yenisei River in 1864 and were brought in from the Netherlands and the United Kingdom across the icy Kara Sea. One was the steamer Nikolai. The steamship Thames attempted to explore the river, overwintered in 1876, but was damaged in the ice and eventually wrecked in the river. Success came with the steamers Frazer, Express in 1878 and, the next year, Moscow hauling supplies in and wheat out. The Dalman reached Yeniseisk in 1881.

Imperial Russia placed river steamers on the massive river in an attempt to free up communication with land-locked Siberia. One, St. Nicholas took the future Tsar Nicholas II on his voyage to Siberia, and later conveyed Vladimir Lenin to prison.

Engineers attempted to place river steamers in regular service on the river during the building of the Trans-Siberian Railway. The boats were needed to bring in the rails, engines and supplies. Captain Joseph Wiggins sailed the Orestes with rail in 1893. However, the sea and river route proved very difficult with several ships lost at sea and on the river. Both the Ob and Yenisei mouths feed into very long inlets, several hundred kilometres in length, which are shallow, ice bound and prone to high winds and thus treacherous for navigation. After the completion of the railway, river traffic reduced to only local service as the Arctic route and long river proved much too indirect a route.

The first recreation team to navigate the Yenisei 's entire length, including its violent upper tributary in Mongolia, was an Australian-Canadian expedition completed in September 2001. Ben Kozel, Tim Cope, Colin Angus and Remy Quinter were on this team. Both Kozel and Angus wrote books detailing this expedition,Five Months in a Leaky Boat: A River Journey Through Siberia, Kozel, 2003, Pan Macmillan and a documentary was produced for National Geographic Television.

A canal inclined plane was built on the river in 1985 at the Krasnoyarsk Dam.

History Nomadic tribes such as the Ket people and the Yugh people have lived along the banks of the Yenisei since ancient times, and this region is the location of the Yeniseian language family. The Ket, numbering about 1000, are the only survivors today of those who originally lived throughout central southern Siberia near the river banks. Their extinct relatives included the Kotts, Assans, Arins, Baikots and Pumpokols who lived further upriver to the south. The modern Ket lived in the eastern middle areas of the river before being assimilated politically into Russia during the 17th through 19th centuries.