months, interrupted by thunderstorms, is usually intense. Snow falls between November and April, but can persist from September to June in the peaks. Important rivers flow through the valleys (including Asif Melloul, Oued n'Fis, and Oued Tessaout) supply the fertile basins like Aït Bou Guemez and Imilchil. These conditions allow the existence of pine, oak and cedar forests. However, these forests are declining because of the reducing of annual precipitation, over-exploitation of the trees (used for construction and heating), and sheep-goat overgrazing. Continental semi-arid or steppe climate, and is present in the southern part of the Central High Atlas, from Toubkal to Imilchil, and the whole Oriental High-Atlas down of Imilchil. These regions are marked by variations in temperatures. It extends southward from the steppe lands into rocky desert. In addition, some localized valleys supplied by irrigation make agriculture possible. Forests are almost rare. This portion of High-Atlas is very similar to the Rocky Mountains in the western United States. Subdivisions Western High Atlas In the west lies the oldest portion of the range. Its high point is the Jbel Toubkal, which is visible from the city of Marrakech. Jbel Toubkal lies in the Toubkal national park, which was created in 1942. The massif consists of Jurassic and Cretaceous formations notched by deep erosion-carved valleys. This part of the range includes the Ourika Valley, which is the only location in the High Atlas where the endangered primate, the Barbary macaque, Macaca sylvanus, is found; however, this primate is also found in parts of the Middle Atlas and the Rif, as well as parts of Algeria. The Ourika Valley is also a location where a diverse flora was recorded as early as the 19th century. Central High Atlas A solid chalk mass morphologically dominated by tabular zones reaching an altitude of extends from Azilal to Ouarzazate. Here, the contrasting landscapes are similar to Colorado in the United States, with high plateaux, gorges and box canyons, and peaks sometimes splintered by erosion. Several peaks in this area exceed , with Jbel Mgoun at 4068 m being the highest peak in this part of the High Atlas. The area is populated by Berbers. Eastern High Atlas The eastern part of the High Atlas forms vast plateaux at high altitude which provide the headwaters for the Moulouya River. It extends from the town of Khenifra. This portion of the range includes the solid mass