 PORTLAND, Ore. - 
 
 Near the Rimrock Draw Rockshelter outside of Riley in southeast Oregon, archaeologists recently discovered evidence suggesting one of the oldest known human occupations in the western United States, officials said Thursday. Bureau of Land Management archaeologist Scott Thomas said that if the age of the site holds up to scrutiny, it would be the oldest west of the Rockies, and another predating the so-called Clovis culture, once generally believed to be the first people to migrate from Asia into North America. The earliest Clovis artifacts, known for distinctive and elegant stone points, are dated to about 13,000 years ago. Near the bottom of a 12-foot deposit, archaeologists discovered a layer of ash that was identified as volcanic ash from a Mt. But the tool, a hand-held scraper chipped from a piece of orange agate not normally found in eastern Oregon, was found about 8 inches below a layer of volcanic ash from an eruption of Mount St. Helens that has been dated to 15,800 years ago. A blood residue analysis of the tool revealed animal proteins consistent with bison, the most likely species being Bison antiquus, an extinct ancestor of the modern buffalo. Dr. Patrick O’Grady, with the University of Oregon Archaeological Field School, has been directing the Rimrock Draw Rockshelter excavations since they began.
– A small stone tool unearthed in eastern Oregon appears to be so ancient that the history of humans in the area may have to be rewritten, archaeologists say. The agate scraper found at a rock shelter was below a 15,800-year-old layer of ash from Mount St. Helens, making it potentially older than any other evidence of human occupation west of the Rocky Mountains, reports the AP. Analysis of the tool—which is made from orange agate not usually found in the area—revealed it had been used to butcher an animal believed to be the extinct buffalo species Bison antiquus, KTVZ reports. University of Oregon archaeologist Patrick O'Grady says the team plans to keep excavating the site after the "tantalizing" find, which may be older than any other find predating the Clovis people once thought to be the first in North America, NBC News reports. University of Washington professor of archaeology Donald K. Grayson, however, predicts there will be a lot of skepticism about the find. "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," he tells the AP. "Until then, extreme skepticism is all they are going to get." (Experts believe they have found evidence of a long-lost civilization in the Honduran rainforest.)