File--This July 23, 2008, file photo, shows the sagebrush desert of Summer Lake Basin and Winter Ridge silhouetted by one of the Paisley Caves near Paisley, Ore. Stone tools and human DNA from the ... more 
File--This July 23, 2008, file photo, shows the sagebrush desert of Summer Lake Basin and Winter Ridge silhouetted by one of the Paisley Caves near Paisley, Ore. Stone tools and human DNA from the ancient Oregon caves offer new evidence of how the first Americans spread through the continent--archaeologists reported Thursday, July 12, 2012, that they have dated broken spear points from the cave to about 13,200 years ago, as old as much different stone tools found elsewhere from the better-known Clovis culture found in the southeast and interior United States.(AP Photo/Jeff Barnard, file) less 
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Associated Press | Photo By Jeff Barnard, file
Thu, Jul 12, 2012 2:53 PM EDT