Cordilleras (kôrdĭlˈərəz, Span. kōrdēyāˈräs) [key] [Span., originally = little string], general name for the entire chain of mountain systems of W North America, extending from N Alaska to Nicaragua. The Cordilleras include the Rocky Mts., the ranges of the Great Basin, the Sierra Nevada, the Coast Ranges, and the Sierra Madre. The name Cordilleras was first applied to the similar systems of W South America, where the mountains stretching from Panama to Cape Horn are known locally as the Cordillera de los Andes (Andes Mts.). Historically geographers used the term cordillera for any extensive group of mountain systems.