24 April 1980. Kalinga pangat (tribal chief) Macli-ing Dulag is killed by government troopers led by Lt. Leodegario Adalem in Bugnay, Tinglayan, Kalinga-Apayao (now Kalinga). The cold-blooded murder of Dulag all the more solidified the opposition of the indigenous peoples in the area to the Chico River Basin Hydroelectric Dam Project. Five years later, the 1st Cordillera Day celebration was held in Belwang, Sadanga, Mountain Province.
For a complete historical backgrounder, see Windel Bolinget's article in Bulatlat.com. For a discussion on the conflict over natural resources in Southeast Asia and the Pacific, read this United Nations University report.
Related post: "Remembering Ka Ambo on Cordillera Day"