During an archaeological survey in order to make way for a construction near a mall, thousands of stone tools were uncovered, dating back to more than 10,000 years ago.
According to lead archaeologist Robert Kopperl, the team was amazed by the discovery, where this is now considered to be the oldest archaeological site in the lowlands of Puget Sound containing stone tools.
This extremely rare find will help scientists gain a better understanding during the time when prehistoric bison and mammoths roamed the Earth particularly in the region now known as west Washington. Also, there are only a handful of these sites that are traced back to 10,000 years or older that have been uncovered in the state.
Based on chemical analysis, the tools revealed traces of food that our human ancestors once ate such as bison, deer, bear, salmon and sheep where researchers also uncovered a salmon bone fragment which suggests that the fish made its way to local streams for more than 10,000 years already.
This site is located just near Redmond Town Center mall in Redmond, Washington that was also surveyed before in 2009 as the city began a project involving the restoration of salmon habitats in Bear Creek which is a tributary of the Sammamish River. Decades before, the creek was used to be confined between a channel lined with rocks.
This salmon restoration project was originally carried out and paid by the Washington State Department of Transportation to offset the environmental effects of building the new Highway 520 floating bridge over Lake Washington along with the widening of the roads.
Kopperl who is also from the SWCA Environmental Consultants, believes that the ancient site was probably occupied by small groups of people who are involved with the craft of making and repairing stone tools. Apart from this theory, Kopperl also suggests that the site is also considered a prime place to camp as it was a centralized location for fishing, hunting and crafting stone tools.
When teams found these artifacts, they continued to dig and investigate deeper where they found a one foot thick layer of peat which is originally from a bog of at least 10,000 years old. Below this peat layer, another wealth of tools and fragments were discovered later.
Kopperl adds that since the artifacts were found under the peat layer that has not been disturbed for thousands of years, it's clear evidence that they predate the peat formation. Radiocarbon analysis further revealed that the charcoal fragments that are detected with the tools, had the same age.
These new discoveries are published in the journal, PaleoAmerica.