| |
13,000
Years Ago
|
By about 13,000 years ago, the climate was warming up and glaciers were beginning to melt. But the landscape left behind by the glaciers was not a welcoming one. Rivers of melting ice and glacial till choked the valleys and created huge glacial lakes that were blocked by ice dams. When the ice dams collapsed, massive floods wasted the landscape. It would be many years before the land could support plant or animal life.
|
|
Along the coastlines, sea levels were on the rise, and coastal lands were flooded beneath the incoming seas. If the first settlers in the Americas did travel by boat along the coast, any archaeological traces of their presence are now deeply submerged under the Pacific Ocean. Archaeologists today try to reconstruct these ancient coastlines so they will know where to look for evidence to support the coastal route hypothesis.
To learn more about ancient coastlines, click Ancient Coastlines
Some areas along the outer coast escaped the glaciers for all or part of the ice age, and remained open and habitable for plants, animals, and possibly humans. Scientists call these areas refugia. Could these refugia have enabled early travelers to make their way by boat down the Pacific coast?
To learn more about coastal refugia, click Coastal Refugia
There are several archaeological sites in the United States that contain fairly good evidence for an early (pre-11,500 years ago) settlement of the Americas. Not all archaeologists accept the evidence from these sites, though, insisting that the only definite human presence in the Americas dates to about 11,500 years ago. What do you think?
Click here to learn more about these early sites:
 Cactus Hill
Meadowcroft Rockshelter
|
|
 |
