The Vercors Massif is a range in France consisting of rugged plateaus and mountains straddling the départements of Isère and Drôme in the French Prealps. It lies west of the Dauphiné Alps, from which it is separated by the rivers Drac and Isère. The cliffs at the massif's eastern limit face the city of Grenoble. Background Over time, various features of the complex geography have been recognised including, the Quatre Montagnes (four mountains), the Coulmes (gorges), the Vercors Drômois (Drome Vercors), the Hauts-Plateaux (high plateaus) and, in the foothills, Royans, Gervanne, Diois, and Trièves. The massif is sometimes called the "fortress." The movement of people tends to be between the massif and the surrounding plains rather than between the various parts of the massif itself. Until the mid twentieth century, the name Vercors was used to describe only the township of La Chapelle-en-Vercors (with Royans), and the northern area around Lans-en-Vercors, Villard-de-Lans, Autrans, and Méaudre (with Grenoble) and was known as the Four Mountains area. In June and July 1944, the massif became important in World War II with the establishment of the Free Republic of Vercors, led by the Maquis du Vercors, a base for the French Resistance against German occupation. The Vercors includes the largest alpine karst area in the Northern French pre-alps, and contains a number of large and deep cave systems. These include Gouffre Berger, which is over deep, and the Réseau de Coufin-Chevaline (grotte de Choranche), a show cave in the Bourne Gorge which has almost of mapped passages. The Vercors has several resorts for cross-country skiing and for down-hill skiing. Villard-de-Lans is the biggest down-hill ski resort. This sporting area is environmentally protected, and although the natural environment has been drastically altered throughout history for the purposes of agriculture and forestry, plans for afforestation will make it one of the major forests of Metropolitan France and a reserve for species such as the southern tulip and black grouse, two symbols of the park, as well as the re-introduced griffon vulture and the alpine ibex. The differences in climate and altitude across the Vercors are reflected in the high level of diversity in the fauna and flora. Etymology The name Massif du Vercors is derived from the name of a local tribe who lived in the area at the time of the Roman conquest of Gaul, who were known as the Vertamocorii (also spelled Vertamocori,