It was originally proposed that Caborca was the protoype for Bac, as Bac was the more elaborate creation, but Robert Goss (1975) has successfully argued that Caborca was modeled after Bac, and dating and stylistic evidence support this idea. Both the floor plans and the facades of the two churches are strikingly similar- Latin Cross Plans with long naves, 2 transepts, and a dome over the crossing. Caborca has 2 sacristy’s, Bac only one, and although Caborca is slightly smaller, their scale is similar. Caborca is often referred to as a shorter, squatter Bac. They both also originally featured Conventos built on the side of Church, off the front at Bac and off the rear sacristy at Caborca although these structures no longer remain at either location.
Scheutz-Miller (2003) and others have analyzed the plans in terms of pre-euclidian geometry and found the same principles at work, the same ratios in both floor plans and elevations, lending credence to the idea that they were built by the same master builder with a single mathematical philosophy in mind.
The names of the Mexican master mason and artisans are not known but several records point to the name Ignacio Gaona as the Master architect. (Fontana, Builders, 1996) An 1880 publication by Bishop Jean Bautiste Salpointe tells of a legend where two brothers named Gaona were employed to build Bac and this story seems to support this idea. Census records indicate that by 1801 one Ignacio Gaona and his wife did indeed live at Bac or in Tucson with their children and his occupation is listed as master mason. (Goss, 1975) Evidence of a brother still remains scarce. However, the name Gaona begins to appear regularly in the parish records at Caborca in 1805 lending credence to the idea that when Bac was completed, the master mason and or his brother travelled south to work on the mission there. (Fontana, Builders) The name is still common in Caborca today. Fontana also tells of an oral history referencing man named Visnak Namkam (The One who meets the Chicken Hawk) who was from Mexico and did all of the interior decorative work alone, although the Indians did assist him. Legend states that one day he left for Caborca and never came back, which is why some of Bac remained unfinished.