Kotlassky District is an administrative district (raion), one of the twenty-one in Arkhangelsk Oblast, Russia. As a municipal division, it is incorporated as Kotlassky Municipal District. It is located in the southeast of the oblast and borders with Krasnoborsky District in the north, Lensky District in the northeast, Vilegodsky District in the east, Luzsky District of Kirov Oblast and Velikoustyugsky District of Vologda Oblast in the south, and with Ustyansky District in the west. The area of the district is 6,300 square kilometers (2,400 sq mi). Its administrative center is the town of Kotlas. Population: 21,005 (2010 Russian census); 24,964 (2002 Census); 32,800 (1989 Soviet census).

Krasnoborsky District is an administrative district (raion), one of the twenty-one in Arkhangelsk Oblast, Russia. Municipally, it is incorporated as Krasnoborsky Municipal District. It is located in the southeast of the oblast and borders with Verkhnetoyemsky District in the north, Udorsky District of the Komi Republic in the northeast, Lensky District in the east, Kotlassky District in the south, and with Ustyansky District in the west. Its administrative center is the rural locality of Krasnoborsk. District's population: 13,815 (2010 Russian census); 17,144 (2002 Census); 20,491 (1989 Soviet census). The population of Krasnoborsk accounts for 34.5% of the district's total population.