Leif Erickson didn’t make it to Minnesota. The settlement he founded was on the Atlantic coast. The Kensington Runestone, a supposed artifact dating from the fourteenth century that indicates a Scandinavian presence in Minnesota at the time, is widely believed to be the product of a hoax or prank.
Widely believed is now less widely. Contemporary research has cast doubt on earlier linguistic analysis that the language on the stone couldn’t have existed in the 14th century.
The Kensington Runestone is real.