Onega River traditionally explained as related to Finnish "Enojoki" - the main river, stream. In terms of both area of the basin and the average discharge, the Onega is the third river basin of the White Sea (behind the Northern Dvina and the Mezen. The river basin of the Onega is spread over the west of Arkhangelsk Oblast, north-west of Vologda Oblast, and also includes minor areas in the east of Republic of Karelia. The Onega basin includes some of the biggest lakes of Arkhangelsk and Vologda Oblasts, such as Lake Vozhe, Lake Lacha, Lake Lyokshmozero, Lake Kenozero, Lake Undozero, and Lake
Primorsky District, Arkhangelsk Oblast first-level administrative division of Russia kept changing. In 1930, the okrug was abolished, and the district was subordinated to the central administration of Northern Krai. In 1936, the krai was transformed into Northern Oblast. In 1937, Northern Oblast itself was split into Arkhangelsk Oblast and Vologda Oblast. Primorsky District remained in Arkhangelsk Oblast ever since. The location of the administrative center of the district was moved several times until Arkhangelsk finally became the center. On December 17, 1940, Belomorsky District was established on the Onega Peninsula, in the areas which previously were parts of Primorsky and Onezhsky Districts. The administrative