Kargopolsky District 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. Kargopolsky District remained in Arkhangelsk Oblast ever since. The district is almost exclusively located in the basin of the Onega River, which is the biggest river in the district, and belongs to the basin of the White Sea. The source of the Onega is Lake Lacha, which is the biggest lake in the district. The northeastern shore of Lake Vozhe, also in the basin of the Onega, belongs to Kargopolsky
Onega, Russia town is also served by the Arkhangelsk–Murmansk rail line, which branches off in Obozerskaya railway station from the railroad between Moscow and Arkhangelsk and runs west to Onega and Belomorsk where it joins the railroad between Petrozavodsk and Murmansk. The railroad was built during World War II to secure the transport of goods from the harbor of Murmansk to central Russia. Onega is connected to Severodvinsk by a road. There are no all-seasonal roads on the left bank of the Onega River. The Onega is navigable downstream from the "selo" of Porog; there is regular passenger navigation. There is also