Father Juan was a native of Querétaro, Mexico. He was born on November 24, 1795. He joined the order at the Convento of Nuestra del Pueblito in 1812. Four years later, at the height of the scandals, he transferred to the College of Querétaro. He came to Tumacácori in mid-June 1824 and stayed six months.
By 1829 there were only four missionaries in Pimería Alta.
1. José María Pérez Llera, Father President of the College of Querétaro and priest at San Ignacio.
2. Rafael Díaz at Cocóspera and ministering to Tumacácori, San Xavier, and the presidios of Santa Cruz, Tubac and Tucson.
3. Juan Maldonado who had returned to Pimería Alta after an absence and was serving at Oquitoa and Tubutama.
4. Faustino González, “a very ill Spaniard at Caborca.”
The missions were in a sorry state. If the missions were not returned to the friars soon, everything the missions owned would end up in the hands of others. The missions were under the Mexican Government. Under the friars the Indians had benefited; they had been fed, clothed, housed and had worked. Now they benefited not at all.
On January 22, 1830, the mission property reverted to the friars’ care. The temporalities Pérez Llera signed for at Tumacácori in 1830 reflected a drastic decline in what Liberós had left two years before. Only some cattle remained because the people of Calabazas, who herded them, had been chased from their homes by Apaches. The mission still had 800 sheep; the horses had gone wild. Crops were unplanted because of Apache peril and lack of demand. The church was as good as new and well enough supplied.
The Governor admitted a staggering debt was owed to the missions by individuals, presidios and the government.
 DCB. Libros de Tubac. Cardoso, Lista.
 Pérez Llera to excelentisimo senor, n.d., ACQ, CS.