The blade dates to the age of the mighty Zoosh, when refugees from Atlantis lived on what is now San Clemente Island and the fire-god, Yangin-Atep, resided in the La Brea tar pits..

The magic, of course, has long since gone away.

"Sea levels then were 50 to 60 meters (about 160-200 feet) below modern levels. Rising seas have since flooded the shorelines and coastal lowlands where early populations would have spent most of their time."

It would seem then that diving expeditions could be most fruitful.

Seems to be more evidence for thor heyerdahl's 1952 book American
Indians in the Pacific idea that Pacific currents were responsible to some extent for early settlement of the Americas,Polynesia,Australia and New Zealand and for a earlier and more sustained settlement than previously thought.