Salinas Pueblo Missions National Monument preserves the remnants of three indigenous villages where Spanish friars started missions nearly 400 years ago. For centuries before Spanish explorers arrived, these pueblos were major trade centers. Salt from nearby dry salt lakes was an important commodity traded between Pueblo and Plains peoples, and its importance led Spanish government officials to call the region the Salinas Jurisdiction. In 1583, explorer Antonio Espejo reported that the area had eleven pueblos with a great many people, over 40,000. A 1760 map by Bernardo Mäera y Pacheco showed the Salinas Jurisdiction stretching from the southern half of the Estancia Basin, along the eastern slopes of the Manzano Mountains, south to Chupadera Mesa and the Tularosa Basin.