As archaeologists surveyed an area in Redmond, WA before a construction project began in 2009, they didn’t expect to find anything particularly interesting. According to a report from the Seattle Times, however, researchers discovered over 4,000 stone flakes, scrapers, spear tips, and awls that were fashioned at least 10,000 years ago by some of the first inhabitants in North America.

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.

The findings of the dig were published in the journal PaleoAmerica, and Kopperl and his colleagues appeared at a presentation this Saturday sponsored by the Redmond Historical Society to discuss the tools.

The tools come from the era right after the ice age, and were likely used by a group of hunters that followed the vast herds of bison and wooly mammoths in Western Washington. Situated on Bear Creek, a tributary of the Sammamish River, the site was likely a base camp for early residents.

A chemical analysis of the tools shows that their owners were eating bison, deer, sheep, salmon, and bear. The camp would have served as a central location for fishing and hunting expeditions.

The tools are a significant find, as archaeological sites in the western Washington area are rarely this prolific. The findings help paint a clear picture of what life may have been like 10,000 years ago directly following the ice age.