The 948 km Marrakech - Casablanca - Kenitra - Fes - Oujda line became known as Chemins de fer strategiques du Maroc and the branch lines diverting from the line as Chemins de fer de penetration du Maroc. These lines were mostly built - with exception of Guercif - Outat Oulad el Hadj - Midelt, which was started in 1916 and completed in 1920 - during the period of 1921 - 1925.