 umnak ()william bright native american placenames of the united states, university of oklahoma press, 2004, isbn 0-8061-3598-0 p. 347 is one of the fox islands of the aleutian islands. with  of land area, it is the third largest island in the aleutian archipelago and the 19th largest island in the united states. the island is home to a large volcanic caldera on mount okmok and the only field of geysers in alaska. it is separated from unalaska island by umnak pass.{{cite web|url=http://islands.unep.ch/itt.
Fox_Islands_(Alaska) Islands_of_Aleutians_West_Census_Area,_Alaska