The
Aleutian Islands (; possibly from
Chukchi aliat, "
island") are a chain of 14 large volcanic islands and 55 smaller ones belonging to both the United States and
Russia. They form part of the
Aleutian Arc in the Northern
Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km
2) and extending about westward from the
Alaska Peninsula toward the
Kamchatka Peninsula in
Russia, and mark a dividing line between the
Bering Sea to the north and the Pacific Ocean to the south. Crossing
longitude 180°, at which point east and west
longitude end, the archipelago contains both the westernmost part of the United States by longitude (
Amatignak Island) and the easternmost by longitude (
Semisopochnoi Island). The westernmost U.S. island in real terms, however, is
Attu Island, west of which runs the
International Date Line. While nearly all the
archipelago is part of
Alaska and is usually considered as being in the "
Alaskan Bush", at the extreme western end, the small, geologically related
Commander Islands belong to
Russia.