Father Gregorio Ruíz was Father Gutiérrez’ third compañero in two years. He came to Tumacácori in late 1805.
He was a Mexican from the Franciscan province of Yucatan. Father Gregorio had affiliated himself with the College of Querétaro on December 20, 1800, and had evidently come to Pimería Alta with Fathers Saravia and Ramírez. He stayed longer than the others, through 1806 and most of 1807. He served also at Cocóspera.
When Father Gutiérrez went with the delegation to Arizpe to draw up new title papers for the lands of Tumacácori he left Ruíz in charge.
Ruíz would serve later at San Xavier del Bac and would die there on January 25, 1817. In fact, Gutiérrez would be called from Tumacácori to attend him, but would reach his side too late, only to learn that “his death had been violent.”
Father Ruíz was Father Llorens successor at San Xavier del Bac.
 See footnote 1 on Manuel Saravia.
 Two folios of Tumacácori baptisms, including Ramírez’ last and Ruíz’ first entries, are missing. Ruíz entered a burial January 4, 1806, and his last baptism on October 20, 1807. DCB. CSCQ, Libro de difuntos.