Although many people think that there was a bridge for that purpose, I doubt there is. If their was a bridge they would have been destroyed and sunken into the ocean. If there is to be one then it would have to go deep into the north pole and back into the Americas.
During the last glaciation so much water, in the form of ice, was locked up on land that sea levels dropped considerably. In the Bering Strait area the level dropped so much people were able to cross from one continent to another aided by the lack of snow in what was a polar desert area.
It was the Bering Land Bridge.
The Bering Strait .
The Bering Straight Bridge used to connect what is now Alaska and Russia.
The Bering Land Bridge was used by the first people who came to the Americas.
The Bering Land Bridge or the Bering Sea Land Bridge.
The Bering Land Bridge.
Bering Strait or Beringia, something with Bering in it
Russia and the United States were connected by the Bering Land Bridge.
Siberia and Alaska.
The Bering Land Bridge.
The Bering Land Bridge, also known as Beringia, was approximately 1,000 miles wide at its maximum extent during the last Ice Age. This land bridge connected Asia and North America, enabling early humans to migrate into the Americas.
The Bering Land Bridge. For mor info and an animated view of the land bridge as it flooded out, see this site: http://instaar.colorado.edu/QGISL/bering_land_bridge/