In less than 1,000 years, these Clovis people and their distinctive stone points made it all the way to the tip of South America.
The people who built campfires there 11,000 years ago had stone projectile points made in the style developed by what are known as the Clovis people.
"If the corridor was closed until 11,000 years ago or afterward," he said, "there is no way the Clovis people could have come through."
One of the oldest cultures yet found is that of the Clovis peoples.
"It wouldn't surprise me that somebody was here before the Clovis people," he said.
But it took a lot of the Clovis people to hunt a mammoth... and even then, they had better watch out!
The first is that the Clovis people hunted them to extinction.
Since the 1950s, archaeologists have believed the Clovis people were the first human inhabitants of North America and that they lived here 13,000 years ago.
The only empirically based evidence is that Clovis people hunted large game.
The Clovis people lived in the Americas about 13,000 years ago.