Bulunsky District is an administrative and municipal district, one of the thirty-four in the Sakha Republic, Russia. It is located in the north of the republic and borders Ust-Yansky District in the east, Verkhoyansky District in the southeast, Eveno-Bytantaysky and Zhigansky Districts in the south, Olenyoksky District in the west, and Anabarsky District in the northwest. The area of the district is 223,600 square kilometers (86,300 sq mi). Its administrative center is the urban-type settlement of Tiksi. As of the 2010 Census, the total population of the district was 9,054, with the population of Tiksi accounting for 55.9% of that number.

Ust-Yansky District is an administrative and municipal district, 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 120,300 square kilometers (46,400 sq mi). Its administrative center is the urban locality of Deputatsky. Population: 6,810 (2021 Census); 8,056 (2010 Russian census); 10,009 (2002 Census); 41,265 (1989 Soviet census). The population of Deputatsky accounts for 37.0% of the district's total population.