Member State of the Arab League Mauritania is divided into 15 regions (wilayat): During the Mauritanian occupation of Western Sahara (1975–79), its portion of the territory (mainly corresponding to the lower half of Río de Oro province) was named Tiris al-Gharbiyya.

[3] The regions (wilaya) are subdivided into 44 departments; see departments of Mauritania for more information.