Municipalities: Alcala, Amulung, Aparri, Baggao, Basco, Calayan, Camalaniugan, Gattaran, Iguig, Lal-lo, Peñablanca, Tuguegarao .
Municipalities: Alcala, Amulung, Aparri, Baggao, Calayan (annexed to Aparri from 1912 to 1920), Camalaniugan, Gattaran, Iguig, Lal-lo, Peñablanca, Tuguegarao, Ballesteros (established 1911), Gonzaga (established 1917) .