KGUN 9NewsAbsolutely Arizona


Rare look inside dome restoration at San Xavier del Bac Mission

Main dome at San Xavier undergoing restoration work
Posted: 3:59 PM, Mar 06, 2023
Updated: 2023-03-06 17:59:23-05
San Xavier del Bac Mission

TUCSON, Ariz. (KGUN) — San Xavier del Bac Mission has been part of the Tohono O’odham Nation for more than 225 years.

To maintain the working Catholic Church takes nonstop preservation efforts. The next phase has begun with conservators working high above the altar.

"This is the main dome, the highest part of the church," said Matilde Rubio.

Rubio is one of the conservators now working on top of 50 feet of scaffolding inside the dome, located above the San Xavier altar.

Scaffolding above the San Xavier altar

They are in the early stages of a four-month project to repair the two-century-old dome.

Matilde and her husband Tim Lewis invited KGUN 9 up top to see the work firsthand.

That means going on the roof of the church, then crawling through a window in the dome, to reach the scaffolding.

San Xavier main dome

"We see things that we never see," Lewis said. "We're all fortunate to see what is up here, but a lot of people will never see it and that's the sad ting about it."

What you cannot see from the floor of the church are the more than 200-year-old paintings on the walls of the dome, in need of restoration.

"This was all flaking," explained Rubio. "Paint flakes were this big. They were hanging. We did the most emergency work we have done."

San Xavier Dome painting

The painstaking work by several conservation technicians includes using a traditional technique. They apply glue with a syringe or brush behind the flake and pushing it back with warm cotton.

Conservation technician working to restore painting on main dome wall

Tim Lewis grew up going to San Xavier and has been working as a conservator here for decades.

"I feel honored to be up here," Lewis said. "I mean our ancestors built this. So it's nice to take care of things that our people did 200 years ago."

This is the second time Lewis has worked on the main dome at San Xavier. In 1994, he helped remove decades worth of dirt and soot.

Tim Lewis entering main dome in 1994

Lewis said they also found something interesting up in the dome in 1994.

"We had found five arrows that people were shooting up here, I guess to kill the bats, because there were bats in here as well."

"We know from what they found in 1994, from their documentation, that things were in pretty rough shape," said Starr Herr-Cardillo, conservation project manager for the non-profit Patronato San Xavier.

"They look a lot better than they did then. But there's a lot of flaking paint and a lot of work that needs to be done."

San Xavier Dome 1994

A major part of that work is repairing several significant cracks in the dome, which were filled in 1994 with plaster.

The plaster is being removed and replaced with the same technique as they used when they built the church. It's a mortar made with cactus mucilage, slaked lime and river sand.

Conservation technician working on a crack in the main dome

All of this work is going on high above the altar, at the top of this giant scaffolding.

"Given that San Xavier is a working church, and it's also a building that requires constant upkeep, that's the constant battle," said Herr-Cardillo. "We do ruin people's visit with the scaffolding but we hope that they understand why this needs to be done."

"They say, 'I'm glad you're taking care of it,' which is very satisfying to us," Lewis said. "Because that's all we're doing, is taking care of something that's 200 years old, over 200 years old."

They are taking care of the Absolutely Arizona history of the White Dove of the Desert.

Once this four-month restoration project on the main dome is complete, it's on to the next project: The front of the church., where they will be restoring the façade.


Pat Parris is an anchor and reporter for KGUN 9. He is a graduate of Sabino High School where he was the 1982 high school state track champion in the 800 meters. While in high school and college, he worked part-time in the KGUN 9 newsroom. Share your story ideas and important issues with Pat by emailing or by connecting on Facebook, Twitter, and Instagram.