World War II wrought heavy damages, death and pain to the people of Mindoro. However, social conditions continued to exist without any definitive changes. After the war, reconstruction and rehabilitation of infrastructure and economy took place which ended with the division of the island into two provinces of Oriental Mindoro and Occidental Mindoro on June 13, 1950, by virtue of the Republic Act No. 505.

In the decades after the war, the island continued to become one of the preferred areas of new settlers coming from the overpopulated provinces in the Philippines in search of the new land. Apart from the hope to become landowners or to have better tenancy conditions, the guerrilla war (Huk rebellion) in Central Luzon was an important factor for migration. Under the settlement program of the National Resettlement and Rehabilitation Administration (NARRA) which was founded on June 18, 1954, families from Central Luzon were settled in the Bongabong-Pinamalayan area. This project ended in 1956 after the settlement of 606 families (3,636 people) on 8,600 hectares of public land. Since then new settlers have incessantly migrated to Mindoro until today.