The territory of the current Valverde province was one of the first non-coastal regions explored by Europeans because it was located to the south of La Isabela, the first city founded on the island.Close to it was the most accessible place to cross the Northern Cordillera, which was named by Christopher Columbus as the Port (or Pass) of Los Hidalgos.Despite these early explorations the territory remained very sparsely inhabited during the colonial era, except for some isolated ranches where cattle roamed.The population, and number of herds, increased slightly during the 17th century with people who had been evicted from Monte Cristi and Bayajá (the "Osorio Devastations") and who preferred to remain in this area, close to their places of origin.South of the city of Mao are the Sierra Samba (a chain of low hills) and part of the Cordillera Central mountain range.