On Unimak Island, Aleutian Islands.
Transliteration by U.S. Bureau of Fisheries (USBF) in 1888 of "So(pka) Shishaldinskaya." Published by Captain Tebenkov (1852, map 24), Imperial Russian Navy (IRN). Seen and reported in 1790 by Captain G. A. Sarichev who gives, according to Grewingk, Agajedan as its native name (Baker, 1906, p. 571).