The High Level Finger Lakes

By Carmelo “Mel” Russo

Following and during the recession of the last glacier over 10,000 years ago, the level of Seneca and Cayuga Lakes was much higher than their present elevation. Blocked by the protruding tongues o£ ice into the Seneca and Cayuga River valleys, the water could not outlet to the north as it does now. The lakes overflowed at some 900+ feet elevation into the Susquehanna River system to the south.

Finger Lakes estate REALLY took a dive during this period!

There is substantial evidence of at least seven different prolonged lake levels, all much higher than present. The water levels were so high that there was no land exposed as far south as Ovid, N.Y.

While doing excavations along the slopes of the uplands one may encounter layers of sand many feet thick between the strata of clay and glacial till. Often the sand outcrops to the surface. These sand layers are the remnants of the ancient shorelines of Seneca and Cayuga Lakes.

Along the northern reaches of the Finger Lakes the sand layers are so thick that the sand is mined commercially. These substantial sand pits arc remnants of the shores of post glacial Lake Iroquios (now Lake Ontario) which extended its sand dunes well into the northern New York townships for many centuries.

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Fig.1 Diagrammatic summary of the Postglacial history of the Great Lakes showing the many available water routes to other drainages. Several of these waterways to the West, South and East were avenues of entry and dispersal for fish during and after recession of ice from the region. Outlets during Glacial times are underscored; general locations of Glacial lake stages are indicated by arrows.  The outlets were never all co-existent and the maximum extent of the lakes as shown was never attained simultaneously in all parts of the basin.