Lake Hitchcock

The lake existed for approximately 3,000 years, after which a combination of erosion and continuing geological changes likely caused it to drain.

At its longest, Lake Hitchcock stretched from the moraine dam at present-day Rocky Hill, Connecticut, to St. Johnsbury, Vermont (about 320 kilometres (200 mi)).

It experienced annual layering of sediments, or varves: silt and sand in the summertime (due to glacial meltwater) and clay in the wintertime (as the lake froze).

Analysis of varves along Canoe Brook in Vermont was conducted by John Ridge and Frederick Larsen, including radiocarbon dating of organic materials.

Later, abrupt changes in sediment composition around 12,400 years ago appear to mark the initial breaching of the lake's dam.