Grassland zone in the southern Sahara Desert, which is occupied by pastoral peoples. This semiarid region of western and north-central Africa extends from Senegal eastward to the Sudan. It forms a transitional zone between the arid Sahara to the north and the belt of humid savannas to the south. The Sahel ("shore" in Arabic) stretches from the Atlantic Ocean eastward through northern Senegal southern Mauritania the great bend of the Niger River in Mali Burkina Faso (formerly Upper Volta) southern Niger northeastern Nigeria south-central Chad and into the Sudan.