Colours represent the first human arrival in a given area.
This period saw the migration of humans into almost all of the Americas through the area known as Beringia, which was comprised of easter Russia, Alaska and the now sunken landbridge connecting the two. While Beringia was first inhabited around 25,000 years ago, humans only moved into much of North and South America between 14,000 and 16,000 years ago. This is likely due to the immense glaciers of North America which, though less extensive in the West, still prevented much movement beyond them.