lasting from 30,000 to 10,000 years ago, an undersea
ridge between Siberia and Alaska emerges from the sea. Known as the Bering Land Bridge, it lies partly south of the ice cap.Gradually, in many separate incursions, the hunter-gatherers of the Siberian steppes pursue their prey across the land bridge and into America. When the melting ice submerges the bridge, about 10,000 years ago, these northeast Asians become isolated as the aboriginal Americans.
HISTORY OF THE AMERICAN INDIANS