In 1562 Francisco de Ibarra headed a personal expedition in search of the mythical cities of Cibola and Quivira; he traveled through the present-day state of Chihuahua. Francisco de Ibarra is thought to have been the first European to see the ruins of Paquime. In 1564 Rodrigo de Río de Loza, a lieutenant under Francisco de Ibarra, stayed behind after the expedition and found gold at the foot of the mountains of the Sierra Madre Occidental; he founded the first Spanish city in the region, Santa Barbara in 1567 by bringing 400 European families to the settlement. A few years later in 1569 Franciscan missionaries led by Fray Agustín Rodríguez from the coast of Sinaloa and the state of Durango founded the first mission in the state in Valle de San Bartolomé (present-day Valle de Allende). Fray Agustín Rodríguez evangelized the native population until 1581. Between 1586 and 1588 a epidemic caused a temporary exodus of the small population in the territory of Nueva Vizcaya.
What caused a temporary exodus from Nueva Vizcaya?
epidemic