Lena

One of the largest rivers of the Russian Federation, in eastern Siberia; length 4,400 km/2,734 mi; total drainage area 490,000 sq km/189,189 sq mi. The Lena rises in the Baikal Mountains, west of Lake Baikal, and flows northeast to Yakutsk, then north into the Laptev Sea (an inlet of the Arctic Ocean), where it forms a large delta 400 km/240 mi wide and covering some 30,000 sq km/11,583 sq mi. The river is navigable almost throughout its course, but is frozen for eight months of the year. Its main tributaries are the Vitim, Olekma, Aldan, and the Vilyui. The main ports on the Lena's course are Osetrovo (since 1954 part of Ust-Kut) and Yakutsk.

In its upper and middle reaches, the River Lena flows through extremely mountainous country. Most of its basin is covered by coniferous forests with perpetually frozen subsoil. Along the Vitim and Aldan rivers, gold is mined; diamonds are found along the Vilyui, and natural gas occurs at the mouth of that river. Much of the basin is underlain by a coalfield, but the inhospitable nature of the terrain means that this is under-exploited. The river's importance as a transport artery grew considerably after a railway was constructed from Taishet on the Trans-Siberian Railway to Ust-Kut on the Lena in the late 1950s. The chief goods exported from the basin are timber, furs, and gold; imported goods include industrial products and food. The Arctic coastal port for the Lena is Tiksi.