Lake Iroquois - Main Phase
As Lake Iroquois grew, further migration of the ice sheet created a panhandle along the northern limit of the Adirondack mountains. This allowed the waters to advance towards the Champlain valley (Vermont/New York) where glacial Lake Fort Ann already existed.
This phase is coined "the main phase" of glacial Lake Iroquois, because this is the highest water levels, and maximum extent Lake Iroquois will experience.