 glacial lake iroquois was a prehistoric proglacial lake that existed at the end of the last ice age approximately 13,000 years ago.  the lake was essentially an enlargement of the present lake ontario that formed because the st. lawrence river downstream from the lake was blocked by the ice sheet near the present thousand islands. the level of the lake was approximately 30 m (~100&nbsp;ft) above the present level of lake ontario. the work of anderson and lewis (1985) is the basis for these authors' views on the history of the postglacial water levels. the lake drained to the southeast, through a channel passing near present day rome, new york. the rome sand plains has several sand ridges that geologists think were formed at this time. the channel then followed the valley of the mohawk river to the hudson river. the lake was fed by early lake erie, as well as glacial lake algonquin, an early partial manifestation of lake huron, that drained directly to lake iroquois across southern ontario, along the southern edge of the ice sheet, bypassing early lake erie. the subsequent melting of the ice dam resulted in a sudden lowering of the lake to its present level, a potential trigger for the younger dryas episode. ==remnant shorelines== two ancient shorelines in the toronto area mark the existence of former glacial lakes. about 2&nbsp;km inland from the shore a ridge known as the iroquois shoreline can be dis
Glacial_lakes_of_Canada Glacial_lakes_of_the_United_States Natural_history_of_Ontario Proglacial_lakes