Plesetsky District
On July 15, 1929, the uyezds were abolished, the governorates merged into Northern Krai, and Plesetsky District was established among others. It became a part of Arkhangelsk Okrug of Northern Krai. In 1930, the okrug was abolished, and the district became subordinate to the central administration of Northern Krai. In 1936, the krai itself was transformed into Northern Oblast. In 1937, Northern Oblast was split into Arkhangelsk Oblast and Vologda Oblast, and Plesetsk remains the center of Plesetsky District of Arkhangelsk Oblast.