Nemuro Subprefecture
Ushishir had no permanent habitation prior to European contact, but was visited in summer by the Ainu tribes from Rasshua, who regarded the island as a sacred land, which they identified as the home of the thunder god. Remains of Ainu huts have been found on the northern slopes of Yankicha's crater bay. Claimed by the Empire of Russia, sovereignty over Ushishir was passed to the Empire of Japan per the Treaty of Saint Petersburg along with the rest of the Kuril Islands. Approaches to the island are difficult due to frequent fogs, rapid ocean currents and the presence of numerous small offshore rocks. The island was formerly administered as part of Shimushiro District of Nemuro Subprefecture of Hokkaidō. After World War II, the island came under the control of the Soviet Union, and is now administered as part of the Sakhalin Oblast of the Russian Federation.