In the United States, the state of Alaska has the longest coastline, which extends for 6,640 miles. Alaska has 33,904 miles of shoreline including islands.
Alaska is the largest state by area, encompassing a massive 663 million square miles. Seventeen of the tallest mountains in the U.S. are found in Alaska, including the highest peak in North America, Mount McKinley. The mountain rises 20,320 feet above sea level. The Yukon River is the third-longest river in the country.
Alaska is surrounded by an estimated 100,000 glaciers and around 70 potentially active volcanoes. It is also the state with the highest frequency of earthquakes.