Complex sentence: It remained strongest in the rugged mostly inaccessible mountain areas of northern Puebla and northern Veracruz states, with the small village of San Pablito in Puebla noted its shamans' production of paper with "magical" properties.
Split into simpler sentences: It remained strongest in the rugged, remote mountainous areas of northern Puebla and northern Veracruz states. Spiritual leaders in the small village of San Pablito, Puebla were described as producing paper with "magical" properties.