[WackyKat]

I see no reason why it couldn't be authentic.
We now know the Vikings established settlements in Canada centuries before Columbus.
I have heard there is some evidence that Portuguese fisherman were fishing off Newfoundland during the late Middle Ages.
Given Columbus' maritime experience, he must have heard some versions of these stories, and perhaps even seen maps of North America.

[blam]

"We now know the Vikings established settlements in Canada centuries before Columbus."

Someone got here waaay before Columbus or the Vikings

European DNA Found In 7-8,000 Year Old Skeleton In Florida (Windover)

[flying Elvis]

The most intriguing evidence I have seen for Europeans in the New World prior to Columbus is the Latin American myths of Quetzalcoatl. They described him as having fair hair, fair skin, and a beard. He left them by embarking in a boat towards the East. When Cortez showed up many years later, many natives thought he was Quetzalcoatl.