Say, wasn’t there an ice bridge from Russia to Alaska at one time? Whatever happened to that?
It was actually a “land bridge” which was several hundred miles wide and existed for hundreds of years. It was formed when sea levels declined during the last ice age. There was a period of time when it was warmer in that region than it is currently, but sea levels were still much lower than they are now. People followed edible wild life and vegetation from Asia to North America and then went further and further South.