Mount Washington has an elevation above sea level of  but has a prominence of about  because it stands that high above its key col — the lowest ground on the ridge line connecting Washington to the higher peaks of the southern Appalachian Mountains. Washington's key col is at the Champlain Canal in New York, the lowest ground on the water divide between the watersheds of the Hudson and Saint Lawrence Rivers.
Mount Washington has an elevation of  but stands out due to its considerable height above its base, which is the lowest point on the ridge connecting Washington to the higher peaks of the southern Appalachian Mountains. The key col for Washington is located at the Champlain Canal in New York, where the watersheds of the Hudson and Saint Lawrence Rivers meet.