The DNA evidence from Kennewick Man and from other even more ancient human remains adds support to a theory that a genetically distinct human population developed in the Bering Strait region on an exposed land area called Beringia that connected Siberia and Alaska when sea levels where lower during the Ice Ages. This population would have lived on Beringian lands for thousands of years, hunting game, before groups within the population began venturing further into North America and along the Pacific Coast, beginning to populate the American continents, perhaps around 15,000 years ago (or possibly earlier). This idea has been dubbed the “Beringian standstill hypothesis” and could explain why early Paleoamericans may have looked different from typical modern populations but nonetheless share genetic links with existing Native American groups.
A controversial archaeological site called Blue Caves, found in the 1970s near the border between Alaska and the Yukon in Canada, included fossil animal bones that appeared to have butchering marks. A date as old as 30,000 years ago was proposed, but was rejected by other researchers. Now a restudy and redating of the bones have apparently confirmed a date possibly as early as 24,000 years ago, making it the oldest archaeological site in North America. If the date is correct, it adds more evidence that humans were in the Beringia region for thousands of years.
Bourgeon L, Burke A, Higham T (2017) Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada. PLoS ONE 12(1): e0169486. doi:10.1371/journal.pone.0169486
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169486
Story of Jacques Cinq-Mars, who first found signs of ancient humans at the cave
https://www.hakaimagazine.com/article-long/vilified-vindicated-story-jacques-cinq-mars
http://westerndigs.org/butchered-bones-found-in-yukon-cave-bear-marks-of-early-americans/