MOUNT VERNON, Va. (AP) — Six millennia after a stone ax was carved, it was rediscovered by a pair of Ohio teens on an archaeological dig at George Washington’s Mount Vernon estate.

The Washington Post reports Mount Vernon officials announced the Oct. 12 find Wednesday. They called it a major discovery that provides a look into the lives of those who lived on the Virginia site before it became the first president’s home.

The 7-inch ax head was found by Archbishop Hoban High School (Akron, Ohio) seniors Dominic Anderson and Jared Phillips while helping map out the dimensions of what’s believed to be a cemetery for slaves and their descendants.

Mount Vernon’s curator of archaeological collections, Sean Devlin, says the ax was dated by comparing it to other tools and looking at the methods of construction.