A person in the United States is anywhere between 282 feet below sea level in Death Valley, Calif., and 20,320 feet above sea level in Mount McKinley, Alaska. MySeaLevel.com allows visitors to enter a ZIP code or physical address for the precise sea level of that location.
Height above sea level is relative to the average height of the surface of the sea and is the same as elevation. Since the tide is constantly rising and falling, hourly observations of the sea's height are taken and recorded over a 19-year period, known as the National Tidal Datum Epoch. The average is referred to as the mean sea level.