 On June 1, 1936 Brusovsky District with the administrative center in the settlement of Brusovo was established as a part of Kalinin Oblast.On November 14, 1960, it was abolished and split between Maksatikhinsky and Udomelsky Districts.On July 9, 1937, Kozlovsky District with the administrative center in the selo of Kozlovo was established as a part of Karelian National Okrug.