Oldest human footprints in American Southwest discovered in Tucson

Human footprints, likely to be the oldest in the American Southwest, have been discovered at a construction site in Tucson. Archaeologists came across the footprints while investigating a piece of land near interstate 10.

Dating back around 2,500 years ago, there are dozens of footprints believed to be of ancient farmers, their children and their pet dogs. Speaking about the discovery, excavator Dan Arnit said that the finding of the first footprints in the Southwest was a huge archaeological experience.

"I found what looked like a heel, and then I went up into this area. And it was like the lottery, and this is the last number I'm scratching off," Arnit said and added, "And when I saw that big toe, I tell you, I was jumping up and down."

The tracks got preserved due to a sudden flood from a nearby creek hundreds of years ago. The fields where the tracks were discovered appear to date to the early agricultural period, between 2500BC and 50AD when some of the first farmers began cultivating crops in the American Southwest.

According to Arnit, the creek overran its banks soon after the prints were made, covering them in its uniquely mica-rich sandy sediment, forming a kind of mineralised cast. There are prints depict the movement of several adults and a child, which were found perfectly preserved at a construction site north of Tucson.

The footprints also provide a glimpse of the daily life of the people who practiced some of the earliest agriculture in the region. "Well, I think I found a time machine. Because the only thing that's missing here is the person standing in the steps," Arnit added.

Jerome Hesse, project manager for SWCA Environmental Consultants – the firm conducting the study – said, "We don't have a firm date, but during phase one [of the excavations], we ran a number of radiocarbon samples, and it's at about that level… from 2,500 to 3,000 years old."

Archaeologists discovered the prints while researching the site for a road is to be redirected through it.