On Santa Rosa Island, one of the Channel Islands just 65 kilometres from Santa Barbara, USA, nearly 20 sites reveal signs of prehistoric human activity. At least nine have what archaeologists say is 'definitive evidence' of ancient Palaeo-Indian occupation, and about half of those date to 11,000 to 12,000 years ago - some of the earliest known settlers of North America's west coast.
     The discovery adds to evidence that maritime Palaeo-Indians lived along the California coast at the end of the last ice age, suggesting that at least some of America's earliest settlers moved south along the coast, rather than farther inland.
     Uncovering hard evidence of this coastal migration has proved challenging, because the shorelines that people would have followed have long since been submerged, but recent surveys have turned up several prehistoric sites that are still on dry land.
     Santa Rosa Island was already famous as the home of Arlington Man - perhaps the oldest human remains ever found in North America, discovered in 1959 and dated to 13,000 years ago. The island's ancient inhabitants left behind a number of unusual crescent-shaped tools made of chipped stone - artefacts similar to those found throughout the Great Basin, typically near water, but whose exact purpose is a topic of debate.
     Dr Torben Rick of the Smithsonian Institution, who led the survey that uncovered the sites, says: "Now the important thing to do is excavate some of these sites in detail to see what more we can learn about ancient cultural practices, environmental changes, and other variables. We of course want to do other surveys like this to find other contemporary sites.

Edited from Western Digs (6 January 2013)