Approximately at the beginning of World War II, the natives of the Mountain Province and the Ilocos Region came to inhabit this vast mountainous land. During that time, the place has no identity yet.

              Most of this vast mountainous land then was owned by a rich old man named Ama Ontoc. Ama Ontoc is very influential, well respected and loved by the people in this place. When the rich old man Ama Ontoc died, the people decided then to call the place after his name.

Drastic changes happened to the place as time passed by including its name which became Amontoc, the result of combining the old man’s name Ama Ontoc into one word.

Families living in that place grew plus continuous migration resulted growth of the Barangay. The first “Teniente Del Barrio” of the place was Lakay Madan (Madan Salungkit) followed by Lakay Oseng (Pedro Oseng) then Lakay Doro (Doro Tagatag). These three leaders dedicated their lives fighting the Japanese invaders during the World War III.

It was on 1992 when Amontoc was officially become one of the Barangays of San Gabriel.