Walking one of my favorite alluvial plains, along the Winooski River. The entire area was once an underwater delta formed in the now extinct Lake Vermont, a produce of melting Ice Age glaciers. As the Laurentide Ice Sheet retreated north, it dammed fresh water that reached as far south as Albany, New York, and north to Warwick, Quebec, with a surface that was about 500 feet higher then its descendant, Lake Champlain. Geologists theorize that about 12,000 the ice dam failed catastrophically, dropping the lake level about 300 feet in a matter of hours. Eventually, the sea swept in temporarily turning Lake Champlain into a saltwater sea. The skeleton of an unfortunately surprised beluga whale that was trapped as the land rose (recovering from being squashed by a mile thick layer of ice) cutting off the lake from the sea is now on display at the University of Vermont. Fresh water eventually displaced the salt water and Lake Champlain was born. Of course, it would not be called Lake Champlain until some modest French explorer, Sammy Champlain, dropped in to name it after himself.