A cordillera is a series of more or less parallel mountain ranges, including their ridges, basins, and tablelands. To this definition, one geographic reference adds the qualification, “belonging to a single orogenic belt.” Orogeny is the process of mountain building, especially the processes of faulting and folding that raised the great mountain ranges of the Earth. The term cordillera came into English from the Spanish, from the word cordilla, which means “string” or “rope.” It was first applied to Las Cordilleras de los Andes, and came to be used to describe North American ranges, especially the Sierra Nevada and the Rockies. The Oxford English Dictionary cites a description of the Andes from 1833 that uses the term to mean lesser divisions of a mountain chain: “At the northern limit of the group of Loxa . . . the main range divides into two subordinate chains, or cordilleras.” Finally, the term has been used to mean the crest ridges of a mountain range. That seems to be Jim Harrison’s sense of it in Legends of the Fall: “By noon they crossed a divide, a cordillera, and turned to take a last view of the ranch.”

Robert Hass