a river in the Yakut ASSR. It is 872 km long and drains an area of 238,000 sq km.

The lana is formed by the confluence of the Sartang and Dulgalakh rivers, which rise in the Verkhoiansk Range, and then flows through a broad, deep valley. After the lana receives the Adycha, the valley widens to 10 or more km, and the river divides into separate channels. As the lana cuts through the northern tip of the Kular Range, the valley narrows, and rapids occur. The lana then follows an extremely meandering path across the Iana-Indigirka Lowland and divides into branches. A delta with an area of 10,200 sq km is formed by the river in the area where it flows into lana Gulf of the Laptev Sea. The principal channels in the delta are the Samadon, which forms the delta proper; the Main Channel (Glavnoe Ruslo), which flows north; and the Right Channel (Pravaia Protoka), which flows to the left of the Main Channel.

There are about 40,000 lakes in the lana basin. The river is fed by rain and snow; it carries up to 90 percent of its annual water volume between May and August. The water level varies by 9 m in the middle course and by 11.9 m at Kazach’e, in the lower course. The mean flow rate is 150 cu m per sec at Verkhoiansk, 925 cu m per sec 381 km from the mouth, and 1,000 cu m per sec at the mouth. The maximum flow rates at Verkhoiansk and 381 km from the mouth are 2,840 and 12,400 cu m per sec, respectively, in the spring and 2,300 and 13,000 cu m per sec, respectively, in the summer. The lana freezes over in October; it freezes solid at Verkhoiansk for 70–110 days a year. The ice breaks up in the second half of May or the first half of June.

The hydropower resources of the lana are estimated at 6.9 million kilowatts. The principal right tributaries are the Adycha, Ol’dzho, and Abyrabyt, and the main left tributaries are the By-tantai and Baky. The lana is navigable; the chief landings are at Verkhoiansk, Batagai, and Ust’-Kuiga. The port of Nizhneiansk is located at the mouth of the river.