Situated in the volcanically active Aleutian Range, it consists primarily of a great dry caldera, which last erupted in 1931.The crater has an average diameter of 6 mi (10 km).

• 位于火山活动频仍的阿留申岭中，主要是一个巨大的破火山口，直径6哩（10公里），1931年最后喷发。