The Department of Environment and Natural Resources (DENR) had its beginnings in the old Department of Agriculture and Natural Resources (DANR). In May 1974, the DANR was split into two departments through P.D. 461 in recognition that natural resources and agriculture are broad and differing concerns. As such, the Department of Natural Resources (DNR) was mandated to ensure the conservation, optimum, utilization, and programmed exploitation of the country's natural wealth including the aquatic resources. With the shift to a parliamentary form of government in 1978, the DNR became the Ministry of Natural Resources (MNR). In 1984, by virtue of Executive Order No. 697, the management of fisheries sector through the Bureau of Fisheries and Aquatic Resources (BFAR), was transferred from the MNR to the Minitry of Agriculture.
The events of February 1986 brought social awareness among the Filipino people that altered the character of the Ministry of Natural Resources (MNR). The creation of DENR under Executive Order No. 131 on January 30, 1987 and the issuance of Executive Order 192 on June 10, 1987 better known as the "Reorganization Act of the Department of Environment and Natural Resources" brought a radical shift in the Department's structure and functions. Pursuant to the Executive Order, the DENR became the primary government agency responsible for the conservation, development and optimum use of the natural resources as well as the protection and development of a sustainable environmental management system for the benefit and welfare of the Filipino people.
The approval of the Philippine Mining Act or R.A. 7945 and implementation of DAO No. 97-11 brought changes to the structure of the Regional Office, relieving Mines and Geo-Sciences Sector from the Region and authorizing this Sector to perform line function.
Changes brought by the passing and approval of the Clean Air Act or R.A. 8749 mandating the Region's Environment Sector to operate as line Bureau. To date, an interim structure has been organized to cater to the needs and demands of constituents in the Mainland Provinces and Island Provinces.
Implementation of DAO 99-14 dated May 05, 1999 provided for the redefinition of functions and realignment of administrative units in the Regional and Field Offices. DAO 99-52 dated December 15, 1999 prescribed a detailed defenition of functions for the realigned regional divisions that finally spelled-out the development and reforms initiatives.
DENR Region 2 is presently located at #14 Dalan Na Pagayaya corner Angicacua, Regional Government Center, Carig Sur, Tuguegarao City. It covers five provinces (Cagayan, Isabela, Nueva Vizcaya, Quirino and the island province of Batanes), four (4) cities (Tuguegarao in Cagayan and Ilagan, Cauayan and Santiago in Isabela) and 89 municipalities and 2,311 barangays. Bounded by three mountain ranges, the Sierra Madre Mountains on the east, Cordillera Mountains on the west, and the Caraballo Mountains on the south, it is criss-crossed by the historical Cagayan River, the longest river and the largest basin in the country. The Cagayan River has a total stretch of about 410 kilometers, a drainage area of 2,811,000 hectares and 1,200,000 ha of major ground water resources.
The province of Cagayan, with 28 municipalities and one city is served by one Provincial Environment and Natural Resources Office (PENRO) and four Community Environment and Natural Resources Offices (CENROs) located in Solana, Alcala, Aparri and Sanchez Mira.
Its nearby province, Isabela, has 35 municipalities and three cities which are served by one PENRO and five CENROs located in Cabagan, Naguilian, San Isidro, Cauayan, and Palanan.
The province of Nueva Vizcaya, served by one PENRO and two CENROs located in Aritao, and Dupax Del Norte has 15 municipalities.
Quirino province with six municipalities has one PENRO and two CENROs in Diffun and Nagtipunan. And the island province of Batanes, with six municipalities is being served by a PENRO only.