The hunter gatherers associated with this technology were thought to have crossed from Siberia into Alaska via a land bridge that became exposed when sea levels dropped. Evidence indicates this occurred as far back as about 13,500 years.
But an increasing number of archaeologists have argued there was likely to have been an earlier occupation based on the stone tools that began turning up at dig sites with claimed dates of more than 15,000 years.
Dr Waters and colleagues say this position is now undeniable in the light of the new artefacts to emerge from the Debra L Friedkin excavation.
Story: Paul Rincon & Jonathan Amos, BBC News | Photo: M. Waters