The Tibesti Mountains are a mountain range in the central Sahara, primarily located in the extreme north of Chad, with a small portion located in southern Libya. The highest peak in the range, Emi Koussi, lies to the south at a height of and is the highest point in both Chad and the Sahara. Bikku Bitti, the highest peak in Libya, is located in the north of the range. The central third of the Tibesti is of volcanic origin and consists of five volcanoes topped by large depressions: Emi Koussi, Tarso Toon, Tarso Voon, Tarso Yega and Toussidé. Major lava flows have formed vast plateaus that overlie Paleozoic sandstone. The volcanic activity was the result of a continental hotspot that arose during the Oligocene and continued in some places until the Holocene, creating fumaroles, hot springs, mud pools and deposits of natron and sulfur. Erosion has shaped volcanic spires and carved an extensive network of canyons through which run rivers subject to highly irregular flows that are rapidly lost to the desert sands. Tibesti, which means "place where the mountain people live", is the domain of the Toubou people. The Toubou live mainly along the wadis, on rare oases where palm trees and limited grains grow. They harness the water that collects in gueltas, the supply of which is highly variable from year-to-year and decade-to-decade. The plateaus are used to graze livestock in the winter and harvest grain in the summer. Temperatures are high, although the altitude ensures that the range is cooler than the surrounding desert. The Toubou, who were settled in the range by the 5th century BC, adapted to these conditions and turned the range into a large natural fortress. They arrived in several waves, taking refuge in times of conflict and dispersing in times of prosperity, although not without intense internal hostility at times. The Toubou came into contact with the Carthaginians, Berbers, Tuaregs, Ottomans and the Arabs, as well as the French colonists who first entered the range in 1914 and took control of the area in 1929. The independent spirit of the Toubou and the geopolitics of the region has complicated the exploration of the range as well as the ascent of its peaks. Tensions continued after Chad and Libya gained independence in the mid-20th century, with hostage-taking and armed struggles occurring amid disputes over the allocation of natural resources. The geopolitical situation and