Long before its formal creation as an independent province, Quirino was the forest region of the province of Nueva Vizcaya, inhabited by tribal groups known as the Negritos. They roamed the hinterlands and built their huts at the heart of the jungle.
Quirino lies in the southeastern portion of Cagayan Valley. It is situated within the upper portion of the Cagayan River basin and bounded by Isabela on the north, Aurora on the east and southeast, and Nueva Vizcaya on the west and southwest.
The Ilocano dialect is used widely in the lowlands of the province’s various municipalities while Ifugao is predominant in the uplands.
Quirino province acquired its juridical personality as a result of the division of the provinces of Nueva Vizcaya and Isabela on June 18, 1966 under RA 4734. Quirino, named after the late president Elpidio Quirino, was created as a sub-province of Nueva Vizcaya in 1966. It became a full province in 1971.
On June 21, 1969, RA 5554 was enacted, amending RA 4734 and creating the municipality of Cabarroguis, now the capital town of Quirino, which was taken from portions of Diffun, Saguday, and Aglipay.
RA 6394 was passed on September 10, 1971 further amending RA 5554 and separating the sub-province of Quirino from its mother province, Nueva Vizcaya, constituting it into a regular province. Hon. Leonardo B. Perez authored RA 6394.
The province of Quirino was formally established on February 10, 1972 upon the assumption to office of the first elected provincial and municipal officials headed by Dionisio A. Sarandi as Provincial Governor.
On February 25, 1983, Batas Pambansa Blg. 345 was enacted, creating within Quirino the municipality of Nagtipunan, a division of the municipality of Maddela.
by: Wikepedia