Pre-Columbian transoceanic contact theories, many of which are speculative, propose that visits to the Americas, interactions with the Indigenous peoples of the Americas, or both, were made by people from elsewhere prior to Christopher Columbus's first voyage to the Caribbean in 1492. Studies between 2004 and 2009 suggest the possibility that the earliest human migrations to the Americas may have been made by boat from Beringia and travel down the Pacific coast, contemporary with and possibly predating land migrations over the Beringia land bridge, which during the glacial period joined what today are Siberia and Alaska. Apart from Norse contact and settlement, whether transoceanic travel occurred during the historic period, resulting in pre-Columbian contact between the settled American peoples and voyagers from other continents, is vigorously debated.
Only a few cases of pre-Columbian contact are widely accepted by mainstream scientists and scholars. Yup'ik and Aleut peoples residing on both sides of the Bering Strait had frequent contact with each other, and European trade goods have been discovered in pre-Columbian archaeological sites in Alaska. Maritime explorations by Norse peoples from Scandinavia during the late 10th century led to the Norse colonization of Greenland and a base camp L'Anse aux Meadows in Newfoundland, which preceded Columbus's arrival in the Americas by some 500 years. Recent genetic studies have also suggested that some eastern Polynesian populations have admixture from coastal western South American peoples, with an estimated date of contact around 1200 CE.
