From there he became involved in the discovery and exploitation of two important silver mining camps, or boomtowns, between 1716 and 1720, at Aguaje southeast of present-day Hermosillo, Sonora, and at Tetuachi, south of Arizpe.
Soon after beginning his military career at Janos, about the year 1722, he married the Captain's daughter, Maria Rosa Bezerra Nieto, and quickly rose to the rank of first lieutenant.
Anza quickly set about whipping the Caballería de las Fronteras (Cavalry of the Frontier) into shape and providing protection to the communities of Sonora from the Apaches.
He assigned soldiers to the San Luis and upper Santa Cruz River Valleys in the Pimería Alta, and settlers began to move into the area.
Returning home from that expedition on May 9, 1740, he evidently rode a little too far in front of his soldiers and was ambushed and killed by Apaches somewhere between Santa María Suamca and the ranch that would become the Terrenate Presidio.