Archeological evidence shows that the Olympic Mountains were inhabited by Paleolithic hunters after the retreat of the Cordilleran Ice Sheet. Stone tools in the Deer Park area date to 7600 years ago, prior to the volcanic eruption of Mount Mazama. Similar tools have been found near Lake Cushman and throughout the Olympic subalpine meadows and ridges, as well as in coastal areas. In addition, a fragment of a woven basket found in the Olympic subalpine of Obstruction Point was radiocarbon dated to nearly 3000 years ago.