Thousands of stone tools crafted at least 10,000 years ago have been unearthed during a standard archaeological survey to clear the way for construction near a mall in the United States. In this region just a small number of archaeological sites dating back by such a huge time frame have been discovered so far.

Archaeologist Robert Kopperl, who led the field investigation, says that the discovery was unexpected, and is the oldest archaeological site in the Puget Sound area that included stone tools. Other unusual tools including bottoms of 2 spear points with concave bases. Scientists were able to discover that bison, deer, bear, sheep and salmon had been consumed by the group of settlers, who lived near Bear Creek.

Initially this site close to Redmond Town Center mall was surveyed in 2009 when the city started a project for restoration of salmon habitat in Bear Creek. Decades before, the creek was used to be confined between a channel lined with rocks. The dig additionally uncovered a fraction of salmon bone, proof that the fish made its means up native streams for a minimum of 10,000 years.

This salmon restoration project was originally carried out and paid by theWashington 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. “They could use it as a centralized location to go out and fish and hunt and gather and make stone tools”.

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.

“It’s hard to find this kind of site west of the Cascades, because it’s so heavily vegetated and the Puget Lobe of the big ice sheet really affected the landscape”, said Kopperl.

He and his colleagues published their initial analysis earlier this year in the journal PaleoAmerica.

The tools were found after the crew found a foot-thick layer of bog remains, dated at least 10,000 years old. Later they discovered a treasure of fragments and tools below the peat.