The Pleistocene glaciers created numerous lakes across the North Country. In many cases, the glaciers scoured lake basins from the underlying bedrock (e.g. the Great Lakes) while, in others, they dammed streams with lobes of ice or glacial till.
A third type of glacial lake, the kettle lake, formed when slabs of ice broke from the glaciers. Generally calving during glacial retreat, these terrestrial icebergs were surrounded and covered by mounds of glacial till. As the climate continued to warm, the ice melted, leaving depressions in the landscape that were later filled by surface streams or ground water flow. Over time, the smaller kettles have accumu-lated thick layers of soil and plant debris, creating northland bogs.
Kettle lakes dot Canada, New England and the Great Lakes States. The most famous kettle lake in the U.S. is Walden Pond, Thoreau's inspirational homesite in Massachusetts. Further south and west, Stage's Pond, north of Circleville, Ohio, is protected in a State Nature Preserve; the pond is a remnant of a larger kettle lake, occupying the north end of the original basin.
