Lal-lo, Gattaran and Lasam are three rural municipalities in northern Cagayan. The former have the Lal-lo and Gattaran Shell Middens and the Magapit Protected Landscape, while Lasam is a smaller municipality that used to be part of Gattaran until 1950.
The present area has been inhabited since prehistoric times. Hunter-gatherers which once roamed the forests of the present municipalities have left traces of prehistoric life such as hunting mollusks in the middens. The sites were discovered by archaeologists in 2000.
Juan de Salcedo, the son of the Spanish conquistador of the Philippines, Miguel López de Legazpi, began the exploration of the area in 1572. Lal-lo was established as Nueva Segovia by the Spanish soldier and landlord Don Juan Pablo Carrión in 1581. Although it appears to have been named after Segovia, Spain, the exact etymology is unknown. The town was the seat of the Roman Catholic Archdiocese of Nueva Segovia at its founding in 1596 as a diocese, until it was moved to Villa Fernandina (now Vigan). Nueva Segovia was renamed to Lal-lo under the orders of Bishop Miguel García to eliminate confusion with the new seat of the diocese.
Until 1839, Lal-lo was a city and the capital of Cagayan until the Spanish authorities moved it to Tuguegarao further upstream. The move was seen as the loss of Lal-lo's position politically and economically, and the present municipal government has been calling for restoring its status as a city and provincial capital.
Gattaran was formed by the merger of three ecclesiastical or church towns, Nassiping, Dummun and the town proper, founded in 1596, 1598, and 1623, respectively. They were merged into the present town in 1873. Lasam was created from the separation of the barrios (present barangays) west of the Cagayan River.
Buses stop at Gattaran town, Magapit junction, and Lal-lo town proper.