Ust-Yansky District

Ust-Yansky District (Усть-Я́нский улу́с; Усуйаана улууһа, Usuyaana uluuha, ) is an administrative and municipal district (raion, or ulus), one of the thirty-four in the Sakha Republic, Russia. It is located in the north of the republic in the Yana River delta on the coast of the Laptev Sea and borders with Allaikhovsky and Abyysky Districts in the east, Momsky District in the south, Verkhoyansky District in the southwest, and with Bulunsky District in the west. The area of the district is 120300 km2. Its administrative center is the urban locality (a settlement) of Deputatsky. Population: The population of Deputatsky accounts for 37.0% of the district's total population.

Geography
The main rivers in the district include the Yana, the Omoloy with the Ulakhan-Kyuegyulyur, the Sellyakh, as well as the Chondon with its tributary the Nuchcha. The Kyundyulyun, northernmost spur of the Chersky Range, rises north of Ust-Kuyga. There are numerous lakes in the district. Orotko is one of the largest.

Average January temperature ranges from -32 to -40 C and average July temperature ranges from +4 to +12 C. Annual precipitation ranges from 150 - 200 mm in the north to 250 - 300 mm in the south.

History
The district was established on January 5, 1967.

Demographics
As of the 1989 Census, the district had a population of 41,265 inhabitants, with an ethnic composition as follows:
 * Russians: 58.7%
 * Yakuts: 8.7%
 * Evens: 2.2%
 * Evenks: 0.1%
 * other ethnicities: 30.3%

However, a great deal of the ethnic Russian population left with the economic downturn following the collapse of the Soviet Union, so much so that the district lost over three-quarters of its population during the 1990s.

In the 2021 census, the indigenous Yakuts again formed a majority of inhabitants, with the total population now just 6,810. In that year, the ethnic composition of the district was:
 * Yakuts: 48.5%
 * Russians: 20.7%
 * Evens: 20.2%
 * Yukaghirs: 2.8%
 * Ukrainians: 2.7%
 * other ethnicities: 5.1%

Economy
The main industries are gold mining, reindeer herding, fishing, and fur trade. There are deposits of gold, tin, tungsten, mercury, lead, zinc, and brown coal.

Inhabited localities
Divisional source:

Population source: *Administrative centers are shown in bold