We continued south to within 20 miles of the Mexican border at Nogales and stopped at Mission Tumacacori along the Santa Cruz River. It was first established in 1691 by Father Francisco Keno, the same priest who began the mission at San Xavier del Bac near Tucson. This mission was never a thriving one because of long distances from Spain for funds and the priests were attacked frequently by raiding Apaches. In 1850, a fort was built at nearby Tubac. The Presidio and its soldiers were there over the next 50 years but it is now only a few walls and a good museum explaining its role in another era.