When the governor of the Spanish colony gave the order in 1606 that everybody living on the northern coast had to move inland, some people came to live around the present Mao. They had cows that were raised in "hatos"; "hato", which means a large farm for raising cattle (a ranch). So "hato" is the name of many places around Mao: Hatico, Hato del Yaque, Hato Nuevo, Hato Viejo, Hato del Medio.