Establishing a coastal migration was once thought to be hopeless.

Evidence of the coastal migration is hypothesized to have been destroyed by the rise in sea levels during the Holocene epoch.

Finding sites associated with early coastal migrations is extremely difficult-and systematic excavation of any sites found in deeper waters is challenging and expensive.

If there was an early pre-Clovis coastal migration, there is always the possibility of a "failed colonization".

The study suggests that the contact could have been trans-oceanic or a late-stage coastal migration that did not leave genetic imprints in North America.

"Our site," he said in a telephone interview, "is about the best kind of evidence you're going to find for the idea of coastal migration - not conclusively probably, but very strong evidence."

"The coastal migration is possible, but neither site provides clear evidence for it at this time," Dr. Sandweiss said.

Early retreat of the Alaska Peninsula Glacier Complex and the implications for coastal migrations of First Americans.

It represents a great coastal migration along Southern Asia, into Southeast Asia and Australia, and up the East Asian coast.

More sites like Monte Verde would need to be discovered to solidify claims of coastal migration, but this may prove difficult as sea levels have risen nearly 200 feet, submerging possible sites.