These groups ranged from various Igorot tribes, a group that includes the Bontoc, Ibaloi, Ifugao, Isneg, Kalinga, Kankana-ey and Tinguian, who built the Rice Terraces. They also covered a wide spectrum in terms of their integration and acculturation with lowland Christian and Muslim Filipinos. Native groups such as the Bukidnon inMindanao, had intermarried with lowlanders for almost a century. Other groups such as the Kalinga in Luzon have remained isolated from lowland influence.
There were several indigenous groups living in the Cordillera Central of Luzon in 1990. At one time it was employed by lowland Filipinos in a pejorative sense, but in recent years it came to be used with pride by native groups in the mountain region as a positive expression of their ethnic identity. The Ifugaos of Ifugao province, the Bontocs, Kalinga, Tinguian, the Kankana-ey and Ibaloi were all farmers who constructed the rice terraces for many centuries.
Other mountain peoples of Luzon are the Isnegs of northern Kalinga-Apayao province, the Gaddangs of the border between Kalinga-Apayao, and Isabela provinces and the Ilongots of Nueva Vizcaya province and Caraballo Mountains all developed hunting and gathering, farming cultivation and headhunting. Other indigenous people such as the Negritos formerly dominated the highlands throughout the islands for thousands of years, but have been reduced to a small population, living in widely scattered locations, primarily along the eastern ranges of the mountains. (Northern Philippines | Wikipedia)