How One State Reaches Both Hemispheres
Alaska seems like the obvious choice for America’s westernmost state, but it also claims the easternmost title when locations are measured by longitude. The reason is the Aleutian Islands, which stretch across the 180th meridian—the line separating east and west longitude—into the Eastern Hemisphere.
Longitude begins at the prime meridian in Greenwich, England, and is measured east or west up to 180 degrees. Alaska’s long island chain reaches almost halfway around the globe from Greenwich. Once the chain passes 180 degrees, the coordinates switch from western longitude to eastern longitude.
The State of Alaska’s geography guide identifies Amatignak Island as the place with the most westerly longitude and Pochnoi Point on Semisopochnoi Island as the place with the most easterly longitude.
Why Flat Maps Make It Confusing
Most flat maps place Alaska on the far left side, reinforcing the idea that the state can only be “west.” However, maps must split the round Earth somewhere, and the usual dividing point is near the 180th meridian. The actual International Date Line bends around the Aleutians so Alaska can remain on the same calendar date, but that political zigzag does not change the islands’ longitudes.
A Geographic Technicality With a Big Payoff
This fact is more than a clever trivia answer. It shows how geographic extremes depend on definitions. By longitude, Alaska is both easternmost and westernmost; by the everyday direction people face when traveling across the Lower 48, Maine still feels easternmost.
It also gives Alaska three remarkable state superlatives: northernmost, westernmost, and easternmost by longitude. That makes the Last Frontier even more geographically unusual than its enormous size suggests. For another surprising state distinction, explore why Hawaii has never recorded a temperature of zero degrees Fahrenheit.
Few map facts overturn first impressions quite so neatly.