Human footprints thought to date to the end of the last ice age have been discovered on the Air Force’s Utah Testing and Training Range (UTTR) salt flats by Cornell researcher Thomas Urban as part of future research.
Urban and Daron Duke of the Far Western Anthropological Research Group were traveling to an archaeological hearth site at UTTR when Urban spotted what appeared to be “ghost tracks” – tracks that suddenly appear for a short time when conditions of humidity are good, then disappear again.
Stopping to look, Urban immediately identified what was familiar to him: unpaved human footprints, similar to those he studied at White Sands National Park, including the earliest known human footprints in the Americas.
“It was a really serendipitous finding,” said Urban, a researcher at the College of Arts and Sciences and Cornell Tree Ring Laboratory.
Researchers returned to the site the following day and began documenting the footprints, with Urban conducting a ground-penetrating radar survey of one of two visible pathways. Since previously refining the application of geophysical methods, including radar, for footprint imaging at White Sands, Urban was able to quickly identify what was hidden.
“As was the case at White Sands, the visible ghost tracks were only part of the story,” Urban said. “We detected many more invisible footprints by radar.”
Duke searched a subset of the prints, confirming they were barefoot and there were other unseen prints. A total of 88 footprints have been documented, including adults and children, offering insight into family life during the Pleistocene era.
“Based on excavations of multiple footprints, we found evidence of adults with children approximately five to 12 years old leaving bare footprints,” Duke said in an Air Force press release. “People seem to have walked in shallow water, the sand quickly filling in their footprint behind them – much like you might feel on a beach – but underneath the sand was a layer of mud that kept the footprint intact after the filling.”
Since there haven’t been wetland conditions for at least 10,000 years that could have produced such footprint tracks in this remote region of the Great Salt Lake desert, Duke said, the footprints likely have more 12,000 years old.
Further research is underway to confirm the discovery.
“We found much more than we bargained for,” Anya Kitterman, Air Force cultural resource manager for the region, said in a statement.
Urban was working at the request of Duke, who had previously found two open pits in the UTTR dated to the end of the Ice Age. On one of these hearths, Duke found the first evidence of tobacco use in humans. These hearths were about half a mile from the newly discovered footprints.
The site has a broader meaning, according to Urban. “We have long wondered if there are other sites like White Sands and if ground penetrating radar would be effective for footprint imaging at locations other than White Sands, as these were a very novel application of technology,” he said. “The answer to both questions is ‘yes’.”
While the Utah site isn’t as old and may not be as extensive as White Sands, Urban said there could be a lot more to be found.
