During the Spanish era, Mountain Province-referred to locally as La Montañosa or Montanyosa-comprised six Comandancias Politico-Militar: Benguet, Lepanto, Bontoc, Amburayan, Kayapa, and Cabugaoan.
Under American colonial rule, the Philippine Commission enacted Act No. 1876 on August 19, 1908, consolidating the entire Cordillera region into a single province named Mountain Province, with Bontoc as its capital. Initially encompassing Amburayan, Apayao, Benguet, Lepanto-Bontoc, Ifugao, and Kalinga sub-provinces, Mountain Province underwent subsequent administrative changes.
In 1920, Amburayan was abolished, and its territories were redistributed to Ilocos Sur and La Union provinces. Similarly, Lepanto's size was reduced, integrating its towns into Bontoc, Benguet, and Ilocos Sur.
On April 7, 1967, Republic Act No. 4695 divided the former Mountain Province into Benguet, Ifugao, Kalinga-Apayao, and the newly reconstituted Mountain Province. These provinces are integral parts of the Cordillera Administrative Region (CAR), established under Executive Order No. 220 in 1987, to cater to the unique cultural and administrative needs of the Cordillera people.
