Aleutian, The. or Aleutan Islands (Russ. Aleut, rock), a chain of islets stretching over the North Pacific Ocean from Kamptchatka to Alaska. Their number exceeds 150, Behring's Island, Copper Island, Attoo, Oonimak, and Oonalashka being the most important. The two former still belong to Russia, but all the others were ceded to the United States with Alaska in 1867. The soil is volcanic, and eruptions still occur in some of the group. The inhabitants subsist mainly by fishing, and export quantities of skins. It has been conjectured that the first colonists of the New World may have found their way from Asia by means of these stepping stones. The group is sometimes known as the Catherine Archipelago, from having been explored in 1760 by the order of Catherine II. of Russia.