|Countries||Georgia and Russia|
|• location||Greater Caucasus, Georgia|
|• elevation||2,700 m (8,900 ft)|
|−28 m (−92 ft)|
|Length||623 km (387 mi)|
|Basin size||43,200 km2 (16,700 sq mi)|
|• average||305 m3 (10,800 cu ft) per second|
The Terek (Russian: Те́рек, IPA: [ˈtʲerʲɪk]; Kabardian: Тэрч, Karachay-Balkar: Терк, Terk; Georgian: თერგი, Tergi; Ossetian: Терк, Terk; Kumyk: Терек-сув, Terek-suv; Chechen: Теркa, Terka) is a major river in the Northern Caucasus. It originates in the Mtskheta-Mtianeti region of Georgia and flows through North Caucasus region of Russia into the Caspian Sea. It rises near the juncture of the Greater Caucasus Mountain Range and the Khokh Range, to the southwest of Mount Kazbek, winding north in a white torrent between the town of Stepantsminda and the village of Gergeti toward the Russian region North Ossetia and the city of Vladikavkaz. It turns east to flow through Chechnya and Dagestan before dividing into two branches which empty into the Caspian Sea. Below the city of Kizlyar it forms a swampy river delta around 100 kilometres (62 mi) wide. The river is a key natural asset in the region, providing irrigation and hydroelectric power in its upper reaches.
The Terek drains most of the northeast Caucasus east into the Caspian just as its sister, the Kuban, drains the northwest Caucasus west into the Black Sea. Its major tributaries are the following. In the west a fan of rivers flows east and northeast into the Terek. These are the east-flowing Malka, the Baksan, the Chegem and the Cherek with its two branches. These three join the Malka just before it reaches the Terek. The Liashen, Urukh, Duradur and Duradon flow northeast, the Ardon and its tributary, the Fiagdon flow north and the Gizeldon drains the north slope of Mount Kazbek and reaches the Terek near the mouth of the Ardon. Then there is the north-flowing part of the Terek with the Darial Pass. The great northwest bend of the Terek is cut off by the northeast-flowing Sunzha which catches most of the north-flowing rivers. These are the north-flowing upper Sunzha, the Assa, the Argun and Khukhulau. East of these are the Aksay and the Aktash which formerly dried up in the lowlands between the Sulak and the Terek. In the east the Sulak drains most of interior Dagestan and turns east to the Caspian before it reaches the Terek.
The Terek river was the site of the final defeat of the army of Hulagu, khan of the Ilkhanate, at the hands of the army of Berke, khan of the Golden Horde, led by Berke's nephew, Nogai Khan, in the first civil war of the Mongol Empire, the Berke–Hulagu war of 1262. Also on the river Timur defeated Tokhtamysh in 1395.
During World War II, German forces at the end of August 1942 reached the Terek near Mozdok – the farthest extent of German conquests in the Soviet Union – but aside from a small bridgehead were unable to forge further toward the oil fields of Baku, Hitler's objective. The Germans penetrated the left bank of the Terek reaching Vladikavkaz suburbs and West Gizel, near the now built weather station.
- Dariali Hydro Power Plant Construction and Operation Project (Environmental and Social Impact Assessment Reportt). Darial Energy LLC. Issued in 2011. Retrieved on 2014-16-07.
- Schramm, Percy Ernst (1963). Kriegstagebuch des Oberkommandos der Wehrmacht, 1940–1945 Teilband II. Bonn: Bernard & Graefe Verlag für Wehrwesen, p.583.