Posted: 30 April 2001

Name usually applied to any region of land that is raised rather steeply above the surrounding terrain. Mountains are distinguishable from plateaux by their usually limited summit area; and they are distinguishable from what are comonly called hills by their generally higher elevation. The elevation, or altitude, of a mountain is given as the height of the summit above sea level. Therefore, a mountain with an elevation of, say, 4,000 m (13,100 ft) may rise to only 3,000 m (9,840 ft) above the surrounding land.Mountains are normally found in groups or ranges consisting of peaks, ridges, and intermontane valleys. Apart from certain mountains that occur singly, the smallest unit is the range, comprising either a single complex ridge or a series of ridges generally alike in origin, age, and form. Several closely related ranges in a parallel alignment or chain-like cluster are known as a mountain system; an elongated series of systems forms a mountain chain; and an extensive complex of ranges, systems, and chains is known as a belt, or cordillera."Mountains," Microsoft® Encarta® Online Encyclopedia 2001 © 1997-2001 Microsoft Corporation. All rights reserved.