According to archaeologists, a stone tool has been discovered in Oregon that hints humans occupied the western US earlier than considered.

It has been informed that the agate tool was found under a thick layer of volcanic ash that dates back to the eruption of Mount St Helens about 15,800 years ago. According to the scientists, it is believed that the primitive knife found 12ft below ground and it might be utilized for butchering meat, cutting animal hides, and carving wood by pre-Clovis people.

An announcement was made by the US Bureau of Land Management that manages the land on which the site was found. The archaeologists have suggested that it might be older than another predating the so-called Clovis culture.

It has been notified that the earliest Clovis artifacts that known for unique and elegant stone points, dates back to about 13,000 years ago. According to Professor Patrick O'Grady from Oregon University, this finding is 'tantalising’. O’Grady said that they would like to carry on digging this summer in order to see whether the volcanic ash covers the whole area.

“No one is going to believe this until it is shown there was no break in that ash layer, that the artifact could not have worked its way down from higher up, and until it is published in a convincing way”, said Donald Grayson, professor of archaeology at the University of Washington.

According to the archaeologists, two pre-Clovis sites are documented and normally accepted by researchers. The one is Paisley Cave at about 60 miles southwest of the Rimrock site and other is the one in Chile. The researchers informed that these both dated about 1,000 years before the oldest Clovis sites.