In 1963, Centre-Ouest Department was created by dividing Sud-Ouest Department. As a result of this division, Sud-Ouest Department was renamed Ouest Department. Using current boundaries as a reference, in 1963 Ouest Department occupied the same territory as Montagnes District.
In 1969, Ouest Department and the other five existing departments of the country were abolished and replaced with 24 new departments. The territory of Ouest Department became the new departments of Biankouma, Danané, Guiglo, and Man.