Aleutian Islands -- Alaska's Aleutian Islands, which consist of 14 large and 55 small islands, were made from volcanic activity. The Aleutians contain 52 volcanoes, with a few of the most active being Cleveland, Okmok, and Akutan. The deep Aleutian Trench, which also sits next to the islands, has been created at the subduction zone with a maximum depth of 25,194 feet (7679 meters).