Северный край
On June 10, 1924, Nikolsky District was established. In 1929, Northern Dvina Governorate was merged into Northern Krai. The krai consisted of five okrugs, one of which, Northern Dvina Okrug, had the administrative center is Veliky Ustyug. Nikolsky District became a part of Northern Dvina Okrug. In July 1930, the okrugs were abolished, and the districts were directly subordinated to Northern Krai. In 1936, Northern Krai was transformed into Northern Oblast, and in 1937, Northern Oblast itself was split into Arkhangelsk Oblast and Vologda Oblast. Nikolsky District remained in Vologda Oblast ever since.