The geographic center of United States, including Alaska and Hawaii, lies west of Castle Rock, South Dakota at 44°58' latitude and 103°46' West longitude. Castle Rock lies in the middle of nowhere in western South Dakota. However, if measured from the prime meridian in Greenwich, England, then Cape Wrangell on Attu Island, Alaska, would be the easternmost point.
|Castle Rock, South Dakota|
Cape Wrangell is considered to be the westernmost point of Alaska and all of the United States by direction of travel. It is located on Attu Island. But, because it sits west of the 180th meridian it can also be viewed as the easternmost point of the United States. Cape Wrangell is not to be confused with the CITY of Wrangell which is located in the Alaska Panhandle; it's located on the island of Attu which has a pretty interesting history.
Attu Station was a former Coast Guard LORAN station. The facility was closed on August 27, 2010,but the airfield remains available for emergency use. The station was established as Naval Air Facility on June 7, 1943, just seven days after Attu Island was declared secured.
Attu Island probably is not a place you would want to visit. The weather on Attu is typically cloudy, rainy, and foggy. High winds occur occasionally. Five or six days a week are likely to be rainy, and there are only about eight or ten clear days a year. The rest of the time, even if rain is not falling, fog of varying density is the rule rather than the exception. There are 39–49 inches of annual rainfall and other precipitation with the heaviest rains in the autumn and early winter.