A mountain range (also mountain barrier/belt/chain/system) is a geographic area containing numerous geologically related mountains. A mountain system or system of mountain ranges, sometimes is used to combine several geological features that are geographically (regionally) related.he Ocean Ridge, the world's longest mountain range (chain). Mountain ranges outside of these two systems include the Arctic Cordillera, the Urals, the Appalachians, the Scandinavian Mountains, the Altai Mountains and the Hijaz Mountains.