Southeastern Arizona has a rich mining history dating back more than 1,000 years.
The indigenous people known also as the Hohokam, or vanished ones, were the first to exploit the vast mineral resources in the area known today as Arizona. They used minerals such as copper and turquoise for ornamental jewelry and to trade among settlements.
Elsewhere in Arizona, Hopi Indians near the present day town of Holbrook mined coal as a means of keeping warm in the winter, for cooking and also for the firing of ceramics. Native Americans were involved in mining turquoise in the Cerbat Mountains and cinnabar in the Castle Dome Mining District near Yuma. They also mined salt near Camp Verde.
There is evidence that the Tohono O’odham mined hematite in the Ajo area for use as war paint in the 15th century shortly after the disappearance of the Hohokam.
Although the O’odham were the first to mine the surface of Arizona, it was the Spanish who were the first to extensively penetrate its earth in search of mineral wealth, most notably in Southeastern Arizona.
The Spanish first entered the region later called Arizona in the early 16th century. Their mission was to obtain the “Three Gs” for Spain — glory, God and gold. The two primary objectives were to Christianize the natives and obtain mineral riches for the Spanish crown.
Early Spanish exploration of Arizona began with the exploration led by Fray Marcos de Niza in 1539.
The following year, his reports of great wealth in the form of gold and silver reached Francisco Vasquez de Coronado, who mounted several pronged expeditions aimed at discovering the “Seven Cities of Cibola” rumored to rival the Aztec and Inca gold caches in Mexico and South America.
The mineral wealth of the fabled Seven Cities proved elusive for the Spanish, though they did succeed in colonizing New Mexico and establishing distant mining claims across the Southwest including Southeastern Arizona.
During the time of Spanish rule, advancements were made in mining and refining minerals.
The Spanish used an arrastra, run by animal power, usually a horse or mule, to pulverize ore deposits of gold and silver. The raw ore was crushed, sometimes amalgamated and later sent to a sluice to maximize the collection of mineral content.
The process of amalgamation was introduced to the New World by the Spanish in the 16th century as a means of separating silver from its ore. Mercury is mixed with silver, removing it from its ore-forming amalgam. The applications of heat or nitric acid remove the mercury from the silver.
Placer mining was also conducted by the Spanish as a low-cost alternative for finding mineral wealth, using techniques such as panning and the sluice box.
The arrival of the Jesuit missionary Eusebio Francisco Kino in the 1690s, along with the added protection of recently established missions of Guevavi, San Xavier del Bac and Tumacacori, gave the Spanish impetus to explore the region for precious metals.
Traveling with his cattle, horses and soldiers to multiple missions in Southeastern Arizona, Padre Kino, an Italian-born Jesuit, was a renowned mission builder and excellent horseman. Kino laid the foundation for the original San Xavier del Bac Mission in 1700 and discovered the Casa Grande Ruins several years previously.
His lengthening the of the Camino Real into Southeastern Arizona and Christianizing the Native Americans served the dual purposes of opening accessibility to mining locations and finding labor with which to mine metals. The Camino Real, known as the King’s Archway, was a route traveled by conquistadors from Vera Cruz, Mexico, to Tucson.
According to the accounts of Father Kino, the Tubac-Tumacacori area was mined by both the Spanish and the Pima Indians for rich veins of gold and silver.
San Xavier Mission, the oldest European structure in Arizona, completed in 1797, was rumored to have $60,000 worth of silver utensils that once adorned its altar. The origin of the silver is believed to have been mines in the neighboring Santa Rita Mountains operated by the padres at Tumacacori Mission.