Land and Resources: Most of the Senegalese country is plains below about 330 feet. Elevations rise to approximately 1640 feet; However, it is only present in the extreme southeast, in the foothills of Fouta Djallon. Senegal also contains 3 main rivers. Senegal which forms the northern border, and Gambia, Saloum and Casamance. Climate: Most regions of Senegal alternate between a dry desert climate and a hot, humid tropical climate in the south. The rainy season in this country lasts approximately from July to October in the north, with an average rainfall of 14 inches, and from June to October, with an average rainfall of 60 inches in the south. The temperatures falling on the cost vary from nearly 22°C in January to 28°C in July. Vegetation and wildlife: The northern part of Senegal is part of the Sahel, a transition zone between the northern Sahara and the humid regions of the south. Vegetation consists largely of savannah grass with scattered trees and shrubs. The vegetation south towards the Gambia River is made up of many trees and further south are mainly mangroves and forests of dance oil, mahogany, bamboo and teak. Wildlife here is diverse and larger animals, such as elephants, cheetahs, lions and antelopes are found more in the less populated eastern half of the country. Crocodiles and hippos are found in most rivers. Senegal is also home to a variety of snakes such as the Cobra and the Boa constrictor. Mineral Resources: Senegal's most exploited mineral spring is found near Thié and contains that of mined phosphates. Also in the late 1970s, oil and natural gas were discovered off the coast of Senegal. Large iron deposits have also been discovered but have not been exploited due to their remoteness. Agriculture: Agriculture provides employment for more than 70% of Senegal's workforce. Crops are closely linked to seasons and rainfall. Crops in the northern part of the country are subject to the effects of rains and droughts. Two different types of agriculture are practiced in Senegal..