11th March 1966
The old Mountain Province was divided into four separate province
On March 11, 1966, the old Mountain Province was divided into four separate provinces,
Mountain Province, with Bontoc as the capital
Benguet, with La Trinidad as the capital
Kalinga-Apayao, with Tabuk as the capital
and Ifugao, with Lagawe as the capital.
The old Mountain Province used to belong partly to the Ilocos Region (Region 1) and the rest to the Cagayan Valley (Region 2).