It also has a working partnership with the Apostolic Vicariate of Tabuk and the Diocese of Baguio, both in the Cordilleras, to coordinate Catholic missions among the Igorot tribes.

The Apostolic Vicariate operates a liaison office in the compound of the Baguio Cathedral.

After a lull for almost a decade, a group of Belgian CICM missionaries led by Constance Jurgens and Jules Sepulchre arrived in Bontoc in time to celebrate a midnight mass on 24 December 1907 On 10 June 1948, Pope Pius XII established the Apostolic Vicariate of the Mountain Province, formerly known as the Apostolic Prefecture of the Montañosa.

Eleven days after, on 21 June, Vatican appointed the Belgian missionary, Bishop William Brasseur as its first Vicar Apostolic.

Assisting the Vicar Apostolic in the governance of pastoral welfare is the Vicariate Mission Council.