This story was originally produced for Cronkite News.
Last week, the Pueblo Grande Museum got a new name. It’s now called the S’edav Va’aki Museum. And unlike most museums that ask you not to touch the artifacts, this one is a little different.
Once a month, while weather allows, volunteers gather at S’edav Va’aki at 44th and Washington streets in Phoenix to throw mud at an over 800-year-old structure. It was built by a civilization culturally related to the O’Odham and Hohokam tribes.
The structure is called a va’aki and it sits on a tall, human-made mound of dirt. The highest room on the mound is the solstice room. The sun lines up perfectly with its two doors during the summer solstice sunrise, and winter solstice sunset. According to a plaque at the site, community leaders would keep track of the solstices to plan harvests and ceremonies.
“The importance of the mudslinging is to preserve the va’aki,” city of Phoenix archaeologist Laurene Montero. “So it’s (an) incredibly strong structure, but the outside of the walls are subject to erosion from the rain.”
Montero said even though the structure has been standing for centuries, it needs constant upkeep.
“So the mudslinging, what we do is go out there and practice stabilization, that would be the more sciency name,” she said.
No one is 100% sure what the va’aki’s original purpose was, but Montero has an idea.
“The Va’aki, or popularly known as the platform mound, is really the last visible part of the village of Pueblo Grande that you can still see, and it was a spiritual kind of place,” she said.
Each room in the va’aki is made up of four cracking dirt walls. There’s a space for a doorway, but no roof. There are paths that go from room to room. Some of the walls are pretty high, making a few rooms look like pits in the ground.
Jim Britton has been a mudslinger for 28 years. His white shirt, white pants and white shoes are spotted with mud.
“We mix up the mud in a big mixing bin, it’s a huge one, usually two guys are mixing it up with a hoe, one guy on each end. One pulls it one direction, the other pulls it the other way, to get it into a consistency that can be easily applied to the eroded area of the walls,” Britton explained.
The mixture is two parts dirt and one part sand.
“And then to that, we’re adding an amendment it’s called,” Britton said. “It’s a polyvinyl acrylic polymer that is used to increase the ability of the dirt to stay in place during rain and stuff, so in other words … Our repair work lasts longer by adding that to the dirt and sand.”
Britton came up with the idea to add the polymer to the mixture in 2000.
After the mixture is created, it’s driven up to the va’aki in a utility vehicle — which looks like a golf cart equipped for off-roading.
Before we can apply the mud to the wall, you have to brush off any loose material that has been eroded.
“And then you wet down the surface,” Britton said. “And then you can take and throw the mud on.”
The mudslingers didn’t just make this up. The method was created by the National Parks Service, and it’s used to stabilize other monuments, too. Throwing the mud gives it enough momentum to stick to the walls.
The museum’s va’aki is one of two in the Valley. There’s another one at Mesa Grande Cultural Park.
“And they were the two largest ones that were known along the Salt and Gila River,” Britton said.
He also said it’s important to keep the structure stable for the next generation.
“We’re saving the past for the future. So when your grandkids wanna see how the people lived 800 years ago, they have a place to go to look at,” he said.
If you’re interested in preserving history, or just need to get your anger out by throwing mud, you can reach out to the S’edav Va’aki museum.
