A team of researchers found a trove of ancient stone tools some 10,000 years old during a dig that was not even aimed toward finding them.

According to The Seattle Times, an archaeologist named Robert Kopperl lead a project surveying an area near Seattle for construction. The researchers found more than 4,000 stone tools including flakes, scrapers, awls, and spear points.

The dig took place near the Redmond Town Center Mall in Redmond, Wash., a town that sits on the opposite side of Lake Washington from Seattle, about 15 miles away. Though Kopperl co-authored a study published in the journal PaleoAmerica on the findings earlier this year, he will discuss the stone tools Saturday at the Redmond Historical Society.

"We were pretty amazed," Kopperl told The Times. "This is the oldest archaeological site in the Puget Sound lowland with stone tools."

Chemical analysis revealed some of the tools were used for eating and traces of animals like bison, deer, bear, sheep, and salmon showed what was on the menu. Surveying for construction in the area began in 2009 and Kopperl's initial findings were not notable, which changed as his team kept going.

"This was a very good place to have a camp," Kopperl said. "They could use it as a centralized location to go out and fish and hunt and gather and make stone tools.

"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."

(Source: Seattle Times)