Artifacts including stone tools and animal bone fragments found in Idaho dating back about 16,600 years represent what may be the oldest evidence of humans in the Americas and offer insight into the routes people took as they spread into the New World. Scientists on Thursday said they used a technique called radiocarbon dating to determine the age of artifacts unearthed at an archeological site called Cooper’s Ferry along the Salmon River in western Idaho near the town of Cottonwood. People were present there at a time when large expanses of North America were covered by massive ice sheets, and big mammals such as mammoths, mastodons, saber-toothed cats, the giant short-faced bear, horses, bison and camels roamed the continent’s Ice Age landscape.
