The Mediterranean-Niger Railway was built between the coal mining region near Bou Arfa in the east of Morocco and the Algerian rail system at Oujda, completed as a standard gauge route between Oran and Oujda in 1922, while Fes was reached in 1934.

[2] In 1940/41, construction was begun on the Algerian segment of the Mediterranean-Niger-Railway as part of the Trans-Saharan Railway.

The line made a connection with the Moroccan segment, which had been completed in 1931, at Bou Arfa and continued into Algeria to connect with the 1,055 mm (3 ft 5+1⁄2 in) narrow gauge line Oran - Colomb-Béchar built in 1910.

[3] In 1963, Morocco nationalized its railroad system under the name of Moroccan Railways (Office National des Chemins de Fer du Maroc ONCF).

[4] The part of MN from the Southern border to Colomb-Béchar was closed.