Father Peña was born in Saltillo, Mexico, in 1709 and had been a Jesuit since 1727. He was having a difficult time as a missionary. He had served at Caborca, but “the superiors had to remove him,” in the words of Father Sedelmayr, “because of his unsuitability for the missions and because of certain disagreements which the Indians had with him.”
However, in February 1744, he came to Guevavi. He may have been sent to observe and learn from Father Torres Perea, or perhaps Father Torres Perea, after three years, had fallen victim to Guevavi’s unhealthful environment and needed the care of a companion.
Whatever the case, Father José Torres Perea, after he recorded the marriage of Juan Miguel Martínez and Juana Romero on February 9, 1744, turned over the mission books to Father Ildefonso. Later that spring, Father Torres Perea left Guevavi.
Through the spring of 1744, the gentle Father Peña survived. In mid-May he had illustrious company. Not since the days of Father Kino had such a high ranking Jesuit come to Guevavi.
Father Visitor Juan Antonio Balthasar, a Swiss destined to become Father Provincial of New Spain, was touring the missions. Because of the lack of facilities for guests at Guevavi, he and his entourage did not stay long.
The natives flocked in from the mission visitas to see the “Padre Grande.” On May 13, 1744, Father Peña baptized six children from Sonoitac and one from Tumacácori. The next day, while he baptized yet another child from Sonoitac, the Father Visitor hinted in a letter that the interim Padre of Guevavi was not staying on.
“If perchance missionaries are on the way (from Europe),” wrote Balthasar, “I beg Your Reverence to bear in mind this province of the Pimería where there are two vacant missions and where two zealous and healthy laborers are needed.”
Ildefonso de la Peña did not qualify and left with the Father Visitor’s party. Once again the Padre’s house at Guevavi was vacant. Once again, Father Keller bore the burden of three missions.
Father Ildefonso died at Onape in July 1745, just a year after leaving Guevavi.
 Sedelmayr to Anzaldo, Tubutama, October 25, 1742; AHH, Temp., 17.
 Keller to Father Visitor Luis María Marciano, February 16, 1741; quoted in Pradeau and Burrus, “Los Jesuitas.” Peña, born in Saltillo in 1709, had been a Jesuit since 1727. He died at Onapa in July 1745, just over a year after leaving Guevavi.
 Peña recorded no marriages while at Guevavi. He wrote his first baptismal entry in February, but failed to give the day, and his last on May 14. His burial entries, if he made any, are missing.
 See Dunne, Balthasar, for a biographical sketch of the Father Visitor and for the circumstances of his inspection tour. Father Dunne apparently did not know that Balthasar visited Guevavi.
 Balthasar to Father Christóbal de Escobar y Lamas, Guevavi, May 14, 1744; AHH, Temp., 17. In the margin someone else noted the need for two “strong and healthy subjects for the Pimería.”