Which U.S. state is the westernmost by longitude?

Alaska is the westernmost U.S. state by longitude, because its Aleutian Islands extend across the 180th meridian.

The answer looks counterintuitive on a conventional map: Alaska is separated from the contiguous United States by Canada and lies close to Russia. Its Aleutian chain stretches westward across the International Date Line’s general vicinity, placing part of the state in the Eastern Hemisphere. That gives Alaska the farthest-west longitude of any state.

The same geography creates a famous technical twist. Since some Aleutian islands lie just east of the 180th meridian, Alaska is also described as the easternmost U.S. state by longitude. In ordinary quiz wording, however, “westernmost state” straightforwardly means Alaska.

Alaska’s western reach also helps explain why it is closer to Asia than any other U.S. state. The Bering Strait separates its islands from Russia, with the Diomede Islands only a few kilometres apart.