Between 1551 and 1552, Diego Fernández de Proaño embarked on several explorations in the Zacatecas region, searching for a legendary hill purported to contain great mineral wealth. He discovered a hill, which despite not matching the descriptions given, bore evidence of rich mineral deposits, which he named “Cerro de Proaño” (“Proaño’s Hill”).
He returned to the city of Zacatecas to report his findings to the Viceroy, but apparently there was not much interest in his discovery and Proaño’s Hill was forgotten over the years.
A second expedition, headed by 15-year-old Francisco de Ibarra, arrived on September 2, 1554 at a place where there was a freshwater spring, in whose border was a “Pequeño Fresno” (small ash).
They decided to spend the night, and Francisco de Ibarra wrote his name for the place in his daily journal: “Ojo de Agua del Fresnillo (spring of the small ash)”.
In the early years after its foundation, the town suffered incursions by Guachichil Indians who were nomadic and bellicose. Due to the heavy losses suffered by the settlers in those early years, the Viceroy, Martín Enríquez de Almanza, ordered the construction of a presidio in the town.
Boner Captain Rodrigo Río de Loza was assigned to lead the garrison of eight soldiers. The military outpost was built where the current municipal palace stands today. Among the first mayors of Fresnillo were Captain Diego Núñez de Miranda, Cristóbal Caldera and Juan de Avellaneda.
Between 1682 and 1757, the mines were worked constantly. There were several mines, mostly on the foothills of Proaño’s Hill.
In 1757, the mine shafts had reached fifty meters in depth and flooding began to be a major problem. The mines were abandoned as it was economically unviable to mitigate the flooding and the area went into an economic crisis.
The mine owners lost their mines as a result of seizure by the Spanish Crown for failure to repay loans. The Crown named a new administrator for the mines, but they continued to lie idle.
In 2013, Fresnillo became the first municipality in Mexican history to elect an openly gay mayor, with the election of Benjamin Medrano.
