It started – as more than a few archeological digs have started – by accident.
In the summer of 2024, the historic Assay Office (built in 1871) in downtown Boise was undergoing a $1.5 million renovation. And when a utility crew began digging a trench to lay in new fiber optic cable, they found something. What the “something” truly was, they had no idea.
But before they began digging, the crew was given strict instruction that if they were to uncover “something” ... they were to notify officials at the Idaho State Historic Preservation Office. Which, quite appropriately, is headquartered inside the Assay Office.
“Our archaeologists immediately went to work, recovering what was inside that trench,” said Dan Everhart, SHPO’s Outreach Historian and Interim Administrator. “So, we knew there was a site here, and that we wanted to do further investigation.”
SHPO partnered with the University of Idaho and its archeological field school; and earlier this year, archeologists were joined by volunteers of all ages and conducted a full-scale dig.
“The University of Idaho has been doing some very interesting things with chemical analyses of the finds…where they can better tell us the origins of the artifacts,” said Everhart. “The University is undertaking what may be months … maybe even a couple of years’ worth of work to better process them, clean them up, assess their content and their quality.”
Inside the Assay Office, just feet away from what was the big dig, Everhart sat down with Morning Edition host George Prentice to talk about the process, how the dig is nearly as important as the findings, and the unique lens he looks through, in the middle of a city that is undergoing rapid change.
Read the full transcript of their conversation below.
GEORGE PRENTICE: It's Morning Edition. Good morning, I'm George Prentice and for this segment of our broadcast, we are in downtown Boise at the Boise Assay Office, one of the most historically important buildings in Idaho. Indeed, this is where the quality and purity of Idaho's precious metals were once tested and certified. Indeed, the gem in the Gem State ended here. So a year ago, crews were digging trenches nearby. They were intent on laying some fiber optic cable. But then, well, here comes a mystery that needed to be solved. Dan Everhart is here. He's with the Idaho State Historic Preservation Office and a friend to this broadcast. Dan. Good morning.
DAN EVERHART: Good morning. George.
PRENTICE: So talk to us about this big dig that was through much of this summer. And what precipitated that and just painted some more picture? Sure.
EVERHART: So in the summer of 2024, as this historic building was undergoing $1.5 Million renovation. All sorts of activities to to make that project happen. And that included new utilities and a trench for a fiber optic cable was being dug across our west lawn. We had told the workers should they uncover something by accident while they worked, that they were to notify us. And so, somewhat to our surprise, they did. They had found some trash, some historic trash in this one foot wide trench. So they stopped their digging. They contacted us and our archeologists went to work, just recovering what was in that one foot wide, maybe three foot deep trench. And it was historic refuse from the historic use of this building. Things related to the assay process and things related to the domestic use of the building. Beginning in 1872, when the building opened for business. The Treasury Department offices were on the first floor, but a three bedroom apartment for the family was on the second floor. The chief assayer and his family. So we found items probably skewed more heavily towards those related to the business of refining precious metals. And then we found things related to the domestic use. So we knew that there was a site here and that we wanted to do further investigation. So having removed the material from the trench, they laid the the pipe. And then almost a year went by before a partnership with the University of Idaho and their archeological field school in late spring, early summer of 2025. And for two full weeks. The University of Idaho and their crew, as well as volunteers and the staff from this office, all participated in a pretty thorough investigation and recovery of a much larger area than just that original trench.
PRENTICE: Pretty serendipitous that it's an historical dig, right? Right, right on the site of an historical structure. Right. Right. I mean, this is what you do. And you drew in. We're we're blessed to have the U of I right there. Archeological expertise. This this sounds pretty great, but. And then you invited the public to participate?
EVERHART: Yes. And we did have members of the public, including younger children, but adults and seniors as well, working to, uh, shake screens and sift dirt and wash artifacts in preparation for their, for their storage and analysis. There was all sorts of folks doing this. College age, as you know, as well as adults and seniors. It was great.
PRENTICE: What years did people live on this site?
EVERHART: For about 60 years, from 1872 until about 1930.
PRENTICE: So when you say refuse, I think it's a very different image of, oh, well, that looks like somebody's trash. I mean, that that is very historical.
EVERHART: Yeah. Yes. But it was absolutely their trash. I mean, it was, it were, it was bits of clothing. So buttons and grommets. We found parts of two, three, four ceramic dolls. The first assayer arrived in 1872. By 1880, he had three daughters under the age of 12. And perhaps these were their dolls. And as they broke, they they discarded them. And then, of course, lots and lots of material related to the work of of assaying precious metal and so glass, metal. And in some cases the sort of dross or heavy metal. So it was an interesting and eclectic dig.
PRENTICE: How about volume in his first quantity? What was the literal takeaway?
EVERHART: Yeah, you have to. You have to remember that sometimes these items are as small as a as a piece of broken metal, no larger than your pinky finger nail. Right. So some, some things, you know, would be mass quantities of probably as many as 10,000 separate items.
PRENTICE: Um, am I correct in assuming that the dig becomes almost bigger than the find? Well, I.
EVERHART: Mean, it's a it's a it's an educational opportunity that we certainly see value in beyond just the educational value of what's recovered. Absolutely. It's our job here at the State Historic Preservation Office to to talk to the public and to represent best practice in archeology and historic preservation. And so to give this educational opportunity to the public was was wonderful. It's probably fair to say that we know a fair amount about the history of American culture in the 1870s or 1880s. So, you know, books have been written on this already. The specific history of this place at that time can be better told by these artifacts. But you're right. In a certain way, the process to uncover the artifacts might be more important than the artifacts themselves.
PRENTICE: Talk to me about process. What? What happens to those thousands of items?
EVERHART: Right. So. So they're recovered. There's just a short window. Right. Um, two weeks in which they're sort of quickly process that is washed, maybe rudimentary, washed and then bagged and tagged, boxed. And now they're at the University of Idaho. So the University of Idaho is undertaking what may be, um, months, maybe even a couple of years worth of work to better process them, clean them up, better count them, assess their content and their quality, do some analytics related to them, and give us some numbers. Write a report. This may occur as early as the end of this coming semester. So say December or or we could be talking about, um, a process that will last into the spring. And depending upon whether or not a graduate student wishes to, they might take this on as a thesis project. And then we've got, you know, another couple of years worth of refinement of that data.
PRENTICE: It's all a surprise, right? I was going to ask. Well, do you expect surprises? But it's all a surprise.
EVERHART: It is. It's interesting. And the University of Idaho has been doing some very interesting things with chemical analysis of the fines, not just these fines, but other archeological finds where they can better tell us the origins of certain chemical residues in the artifacts. And that's especially important because our certainly the assaying artifacts were very much chemically derived. And so you could see how that sort of information would be would be valuable. There's there's going to be there's going to be information that comes out of this that we didn't know about, and we don't know what that is yet.
PRENTICE: We are sitting here in the assay building. This is an historical landmark, right? Yeah. Um, and I think a lot of people, well, tens of thousands of people walk or drive past here every day, right? Where? Kitty Porter from the Labor Department, but is still a bit of a mystery here, right? Yes.
EVERHART: Yeah, yeah. No. People question what this place is. And. And you know, sometimes carefully, slowly open the front door. It creaks when they do. And, and they wonder if they're allowed in. They are. Um, but.
PRENTICE: Again precious metals were, were tested here and cataloged here. Yeah.
EVERHART: Yes. Um, refined before often during that early history being purchased essentially by the Treasury Department and stored here on a temporary basis before eventually, according to Treasury records, the gold and silver collected here was shipped to Philadelphia to be used in minting the nation's coinage. It was an active Treasury Department installation for its first 60 years and, um, millions of dollars of gold and silver.
PRENTICE: Which is why there used to be bars on the windows. That's right.
EVERHART: Yeah. There used to be bars on the windows. Another mystery. Yeah. That's that. Those bars came in a little later after it was built, but by 1890 or so there was some element of security on the on the first floor windows.
PRENTICE: You are an historian by trade. We are here in Boise's downtown core. I'm curious about the unique lens that you look through in a city that is changing so rapidly.
EVERHART: Yeah, change is important. Change is is present everywhere we look. The way we react to that change, the way that we manage that change, has a crucial impact on our built environment and on the history that we continue to see or the history that we lose. And so we must be careful as we continue to change and change. We will to not lose that history, to not accidentally or maybe even occasionally on purpose, a race, the documentation, the built environment, the documents that history. This building itself was threatened with removal. During the 1960s, there was one proposal to put the new federal building on this site, a block square in downtown Boise. There was an outcry from the public, and ultimately Senator Church put a stop to the the removal of this building and the use of the site for a federal building. But while this property is now protected, much of our downtown remains unprotected.
PRENTICE: We break ground on a pretty rapid basis here.
EVERHART: Absolutely. And we can be careful. We can we can be better at that. We don't have to lose the the benefit of growth and change, but we can do so in a careful way.
PRENTICE: Dan Everhart is State Historic Preservation Office outreach historian and interim administrator. Thanks, Dan.
EVERHART: Thank you, George.
Find reporter George Prentice @georgepren
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