The formation of Lake Ontario
Like much of the geography of Western New York, Lake Ontario and the area of Hamlin Beach State Park were formed when the last glaciers receded about 10,000 years ago. Melting water accumulating at the southern edge of the ice sheet formed Lake Warren, a large lake which covered most of western New York State. As the glacier melted further, this lake disappeared and the water ran into an area north of the present-day Ridge Road, US Route 104. It then formed Lake Dawson, located in the vicinity of the basin now called Lake Ontario.
The glacier shelf that blocked the eastern end of Lake Dawson finally disappeared and the waters mixed with the salt water of the Atlantic Ocean, creating a salt-water body called the Gilbert Gulf. As years passed, the weight of the ice diminished and the land in the St. Lawrence Region rose, separating the ocean from the inland waters, creating Lake Iroquois. The sand and gravel from the shores of this lake provided the base of the aforementioned Ridge Road. The lake continued to grow and spilled over this landmass, cutting through the land and creating the St. Lawrence River. As fresh water diluted the salty body, the lake became fresh. The body of water that formed is Lake Ontario.




