When did humans arrive in North America?

This was the San Diego of 130,000 years ago, as it would have appeared to early humans who, according to controversial new research, may have lived there. Recently discovered stone tools and the broken bones of a mastodon these humans apparently attacked are evidence archaeologists may have gotten early human history completely wrong. Because up until now, researchers believed Homo sapiens or their predecessors were not in the Americas until about 20,000 years ago.