Russian Empire Bolsheviks followed in 1918. The administrative boundaries of European Russia, apart from Finland and its portion of Poland, coincided approximately with the natural limits of the East-European plains. In the North it met the Arctic Ocean. Novaya Zemlya and the Kolguyev and Vaygach Islands also belonged to it, but the Kara Sea was referred to Siberia. To the East it had the Asiatic territories of the Empire, Siberia and the Kyrgyz steppes, from both of which it was separated by the Ural Mountains, the Ural River and the Caspian Sea — the administrative boundary, however, partly extending into Asia on
Severnaya Zemlya of the Severnaya Zemlya group and is separated from Komsomolets Island by the Yuny Strait. Pioneer island measures in area. This island houses the Pioneer Glacier. Thelodonti fossils from the Upper Silurian have been found in the island. Off Pioneer Island's southwestern end lies Krupskoy Island. This is a fairly large island, over in length and about in width. The sound that separates it from Pioneer is only in width. This island should not be confused with Pioneer Island in Canada (). Schmidt Island, measuring , is located at the far northwestern end of the archipelago. This island is quite