the Yukon River begins in Canada's Yukon Territory.
many other rivers flow into it as it runs from east to west across central Alaska.
some of the rivers are fed by melting glaciers.
this gives the Yukon its strange whitish, or milky, color.
the river generally freezes in October and melts again in May.
Large ice dams sometimes form and cause large-scale flooding.
As the Yukon nears the Bering sea, it breaks into many smaller river, forming a delta.
this fact makes it impossible for large ships to travel up the river