This article is about the Russian river. For the "language" Ob, see Gibberish.

Ob (also Obi, Russian Обь) is a river in West Siberia, Russia, the country's longest.

It is known to the Ostiaks as the As, Yag, Kolta and Yema; to the Samoyedes as the Kolta or Kuay; and to the Siberian Tatars as the Omar or Umar.

It is formed 8 mi. southwest of Biysk in Altai Krai, by the confluence of the Biya and the Katun. Both these streams have their origin in the Altai (Sailughem) Mountains, the former issuing from Lake Teletskoye, the latter, 80 mi. long, bursting out of a glacier on Mount Byelukha . The Ob zigzags west and north until it reaches 55° N, where it curves round to the northwest, and again north, wheeling finally eastwards into the Gulf of Ob, a deep (600 mi.) bay of the Arctic Ocean.

The river splits up into more than one arm, especially after joining the large river Irtysh in 69° E. Originating in China, Irtysh is actually longer than Ob to their confluence. Other noteworthy tributaries are: from the east, the Tom, the Chulym, the Ket , the Tym and the Vakh; and, from the west and south, the Vasyugan, the Irtysh (with the Ishim, the Tobol), and the Sosva .

The navigable waters within its basin reach a total length of 9300 mi. By means of the Turn, an affluent of the Tobol, it secures connection with the Ekaterinburg-Perm railway at Tyumen, and thus is linked on to the rivers Kama and Volga in the heart of Russia. Its own length is 3700 km (2260 mi.), and the area of its basin 2,600,000 km² (1,125,200 sq. mi.).

The combined Ob-Irtysh system, the second longest river system of Asia, is about 5410 km (about 3362 mi.) long. The largest river port is on Irtysh in Omsk, with a link to the Trans-Siberian Railway. A system of canals, utilizing the Ket river, 560 mi. long in all, connects the Ob with the Yenisei.

The Ob is ice-bound at southern Barnaul from early in November to near the end of April, and at nothern Salekhard, 100 mi. above its mouth, from the end of October to the beginning of June. Its middle reaches have been navigated by steamboats since 1845.

Cities along the river include:

• Barnaul
• Novosibirsk (Russia's third largest)
• Kolpashevo
• Nizhnevartovsk
• Surgut
• Salekhard

See also: Rivers of Russia

External links

• Information and a map of the Ob's watershed