Read books by Frederick Pohl. (not the Sci-Fi writer, another one) He researched early Euro contact with N. America. I think he did pin-point the Viking Vinland as Folins Pond on Cape Cod in Mass. He found a ships shoring where a two pointed boat (Viking type) was drawn up on shore (stakes on rocks to support the keel and post molds) and mooring holes in rocks in the pond. Viking descriptions of the landscape fits. The area is now a housing development. No mention of other direction, west to east, but most agree there was extensive fishing off the N. Amer coast for hundreds of years before Columbus.