Ancient ‘ghost footprints’ preserved in mud are ‘once in a lifetime’ find

Footprints discovered on an archaeological site are marked with a pin flag on the Utah Test and Training Range (U.S. Air Force photo by R. Nial Bradshaw)
Footprints discovered on an archaeological site are marked with a pin flag on the Utah Test and Training Range (U.S. Air Force photo by R. Nial Bradshaw) (r.nial.bradshaw)

Archaeologists have unearthed footprints preserved in mud thought to date from 12,000 years ago.

Preserved in an alkali flats in a firing range, the footprints come from human adults and children who walked across mud more than 10 millennia ago – and are known as ‘ghost footprints’ because they are visible when wet.

The 88 human footprints are thought to date from the Pleistocene era, 12,000 years ago and were found on the Utah Test and Training Range.

“We found so much more than we bargained for,” said Anya Kitterman, Hill Air Force Base’s cultural resource manager.

“These are once-in-a-lifetime discoveries and I feel blessed that I’ve been able to be a part of them as well as find ways in which to bring them to the public,” she added.

Kitterman is now overseeing a 5,000-acre archaeological survey and a pilot study on the use of non-invasive archaeological techniques, including use of a magnetometer and ground penetrating radar, while the busy range undergoes annual maintenance and upkeep.

The prehistoric footprints discovery, at what is now being called the Trackway Site, complements 2016 discoveries made nearby at the Wishbone Site.

The sites are located within a half mile of each other.

An open-air hearth, or fire pit, that dates to about 12,300 years ago, was found at Wishbone, along with burnt bird bones, charcoal and numerous artefacts such as Haskett projectile points and stone tools.

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Evidence was also found for the earliest known human use of tobacco in the world.

Principal investigator Dr Daron Duke said the most surprising and telling thing about finding the footprints is the insight it provides into the daily life of a family group thousands of years ago.

“Based on excavations of several prints, we’ve found evidence of adults with children from about five to 12 years of age that were leaving bare footprints,” he said.

“People appear to have been walking in shallow water, the sand rapidly infilling their print behind them - much as you might experience on a beach - but under the sand was a layer of mud that kept the print intact after infilling.”

“Our long-term work on the geochronology of this area suggests these prints are likely more than 12,000 years old,” he said.

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Even with the area now part of an active weapons and training range, Duke said in many ways, this serves as a “preserve” for these archaeological sites.

“The Air Force has been very supportive and facilitating of the Trackway find,” he said. “They have a mission to complete, and for years Hill AFB has done this while preserving and protecting the archaeological record.”

“We have also collected the infill of the prints to see if we can find organic materials to radiocarbon date,” Duke said. “We want to further detail the prints themselves as to who comprised the group and how they were using the area. We are also talking to Native American tribes about their perspectives on the prints.”

Duke said they were fortunate to have several tribal representatives visit the sites of their early ancestors.

“There is an immediate human connection to seeing human footprints,” he said. “To see them from a distant past, especially so much different than it looks today, can be impactful.

"They were very happy to see this, and it was personally rewarding for me to be able to show it to them. We will continue to talk to them about it.”

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