Home Artifacts Arizona archaeologist says she found artifacts linked to famous 1540 expedition: ‘A site that changed history’

Arizona archaeologist says she found artifacts linked to famous 1540 expedition: ‘A site that changed history’


A Tucson archaeologist has unveiled a find in Santa Cruz County that she says could rewrite the history of the Coronado Expedition. Deni Seymour said he unearthed hundreds of artifacts linked to the 16th-century Spanish expedition, including pieces of iron and copper crossbow bolts, distinctive hawkhead nails, a horseshoe and a spur medieval, a sword tip and pieces of chainmail armor.

The ‘artifact trophy’ is a bronze wall gun – over 3 feet long and weighing about 40 pounds – found sitting on the floor of a structure which she says may be evidence of the oldest European settlement on the American continent.

Explore Francisco Coronado
Francisco Coronado on a 1540 expedition from Mexico through the American Southwest. 1905 lithograph of a painting by Frederic Remington.

Universal History Archive/Universal Pictures Group via Getty

“It’s a site that changes history,” said Seymour, who bills herself as the Sherlock Holmes of history. “It’s unmistakably Coronado.”

The independent researcher revealed her discovery on January 29 during a sold-out conference in front of more than 100 people at the Tubac Presidio State Historic Park.

Seymour does not divulge the exact location of the archaeological site, but his general description in the Santa Cruz Valley places it at least 40 miles west of the Coronado National Memorial, which overlooks the San Pedro River and the US-US border. Mexican south of Sierra Vista.

In 1540, Spanish conquistador Francisco Vázquez de Coronado led an armed expedition of over 2,500 Europeans and Mexican-Indian allies across what is now Mexico and the American Southwest in search of riches.

The two-year journey took them as far north and east as present-day Kansas and brought them into contact – and often conflict – with centuries-old native cultures along the way.

Although professional archaeologists and amateur sleuths have wondered about it for nearly 150 years, Coronado’s exact route through Arizona to the elaborate Zuni pueblos of northern New Mexico remains a mystery.

The consensus among scholars is that the expedition most likely followed the Rio Sonora through northern Mexico and the San Pedro River into what is now Arizona.

Seymour believes his discovery proves once and for all that Coronado and company entered Arizona along the Santa Cruz River before eventually heading east.

Deni Seymour


This puts her at odds with most researchers.

Bill Hartmann is an accomplished astronomer from Tucson, who has also researched and written about Coronado for over 20 years. In 2014, the University of Arizona Press published their book on the subject, “Searching for Golden Empires”.

“Looks like she’s got a really exciting site,” Hartmann said after attending Seymour’s first lecture in Tubac. “The big question in my mind is whether this disagrees with the previous interpretation of where the Coronado expedition went. I don’t think it undermines previous thoughts that they came to San Pedro .”

New Mexico historian Richard Flint had a similar reaction: excited by Seymour’s discovery, skeptical of his conclusions.

Flint and his historian wife, Shirley Cushing Flint, are among the world’s foremost experts on the expedition. In over 40 years of research, they have written eight books and countless academic articles on the subject.

“I think Deni’s findings are certainly fascinating and likely point to the presence of the Coronado Expedition,” Flint said. “I don’t think that means the usual rebuilding of the route to the north should be abandoned. The evidence is very strong that they went through the Rio Sonora.”

Seymour also said she once favored the San Pedro route. But that was before all of these artifacts ended up in an entirely different river valley.

She said she first visited the site in Santa Cruz County in July 2020 and immediately found several hawkhead nails, “which in that area definitely means you have Coronado.”

Since then, she has been discovering artifacts there using metal detectors and a team of 18 volunteers, including several members of the Tohono Oʼodham tribe.

“The site keeps on giving and giving,” she said.

Relics have been unearthed over an area that stretches for more than half a mile. At a minimum, says Seymour, it’s the remains of a large encampment, but she suspects it’s something more.

“What we have is a named place,” she said, “a named place in the Coronado logs.”

Seymour believes he has found the remains of Suya, also known as San Geronimo III, as it was the third and northernmost of a Spanish outpost established to support the expedition.

In addition to the central structure where the wall gun was found, she said she identified what appears to be six surrounding watch stations, three of which show “clear evidence of an attack.”

The Spanish “had a major presence here, and they had major conflicts with the natives here,” Seymour said. “And they are different natives than previously thought.”

Based on the location of the site and the items she found, she is confident that the outpost was not routed by the Opata people who once ruled what is now Sonora, but by the Sobaipuri, whose direct descendants include the Tohono Oʼodham in San Xavier.

Distinctive pellet clusters and arrowheads from Sobaipuri tell the story of their final confrontation, which sent the Spaniards back south.

“We have clear evidence of battle,” said Seymour, who has written dozens of books and scholarly articles about the area and its early native inhabitants. “There is no question.”

Excavations at the site have so far yielded over 120 socket head nails and over 60 crossbow bolts.

These are the most “diagnostic” artifacts from the Coronado expedition, Flint said, and finding that many crossbow bolts in particular is compelling evidence of a significant skirmish.

According to Flint, there are a number of accounts written by members of the expedition that refer to Suya and the battle that led to her abandonment. He said the loss of the outpost “sort of put the nail in the coffin” of Coronado’s journey, as it cut him off from his main supply and communication route.

Whether this is the first European colony in the United States seems to depend on how you define the word colony.

To Hartmann, Suya looked “more like a struggling military garrison than a town”, he said.

And it wasn’t the first either way, Flint added. By the time San Geronimo III was created, Coronado had already traveled deep into present-day New Mexico, where the expedition encountered natives and lived for months in some of their captured pueblos.

“Everybody wants to be the first. (This discovery) is important, even if it’s not the first,” Flint said. “Virtually everything that is discovered about the Coronado expedition has the chance to shed new light on something that was not known.”

Seymour is much less measured. For her, this discovery is so important, so revolutionary that it could one day become a national monument or a world heritage site.

“There are a lot of naysayers,” she said. “I’m an archaeologist. I just go where the evidence is.”

Seymour plans to publish the first of several peer-reviewed papers on his discovery this spring. She said she had already received some radiocarbon results and other dating methods to support her, with further tests planned.

Regarding her recent public lectures in Tubac, Seymour said she took the unusual step of selling tickets and publicizing her work early in order to raise funds for an in-progress documentary about the discovery of Frances. Causey Films, based in Tucson.

“As archaeologists, we can see the coolest things” and go places others can’t, she said. “(The documentary) is important for people to see and understand the process of discovery.”

Just over $8,400 had been raised for the film so far, but the crowdfunding campaign was still well short of its $100,000 goal.

Seymour didn’t keep the dig site entirely to herself. Over the past year, she’s shared photos of the artifacts with several experts, including the Flints, and invited a handful of fellow researchers to see where she’s working.

She said she only brings people she can trust, and only on the condition that they do not reveal the location or take anyone else there on their own.

Seymour knows she can’t keep the site a secret forever, but she wants to protect it for as long as she can.

“We still have a lot of work to do,” she said. “I don’t want to compete with treasure hunters.”

The longtime southern Arizona researcher also claims to have found Coronado artifacts at two other locations about 6 miles apart in the San Bernardino Valley, about 100 miles as the crow flies east of its main site in Santa Cruz County.

She predicts that these discoveries will eventually help determine the exact route of the infamous expedition through Arizona.

“We now have an anchor,” Seymour said. “I think we’re going to start finding a lot more Coronado sites.”