After the declaration of Martial law by Ferdinand Marcos in 1972, the region became the focus of militarization as a result of local objections to the government's push for the Chico River Dam Project near Sadanga, Mountain Province and Tinglayan, Kalinga. Frustrated by the project delays caused by the opposition, Ferdinand Marcos issued Presidential Decree no. 848 in December 1975, constituting the municipalities of Lubuagan, Tinglayan, Tanudan, and Pasil into a "Kalinga Special Development Region" (KSDR), in an effort to neutralize opposition to the Chico IV dam.