North America and Asia are separated today by a narrow ocean channel called the Bering Strait. But during the ice age, when much of the earth’s water supply was locked in glacial ice, sea levels worldwide dropped and a land bridge emerged from the sea and connected the two continents. The Bering Land Bridge environment was very dry, so most of it remained free of glaciers throughout the ice age. (Glaciers are made from snow and ice, so if no snow or rain falls, a glacier cannot form). Vegetation consisted mainly of grasses and low shrubs, which was ideal food for woolly mammoths, horses, caribou and bison. Most scientists think this was the route traveled by the first settlers of the Americas, as they followed these grazing animals from Siberia into Alaska and from there to the rest of North and South America.
As the climate warmed up, glaciers began melting and sea levels around the world began rising. By about 11,600 years ago, the Bering Land Bridge had once again disappeared beneath the Bering Strait.
