The lakes of this region are of two kinds: (1) those due to the
damming of river valleys by glacial deposits and (2) rock basins
gouged out by the ice.
Among the lakes which owe their origin to drift accumulations in the
valleys are Andrew and Haines' ponds at the head of Still River. These
are properly parts of the Croton River system, but Andrew Pond has
been held back by the deep filling of boulder clay in the valley. Lake
Kanosha, in the same valley, is a shallow lake formed in the drift.
The lake south of Spruce Mountain at the head of the Saugatuck seems
to be enclosed by drift alone.
Neversink Pond, Barses Pond, Creek Pond, and Leonard Pond are the
remnants of larger water bodies now converted into swamps. Squantz
Pond and Hatch Pond have dams of drift. Eureka Lake and East Lake
appear to be rock basins whose levels have been raised somewhat by
dams of till. Great Mountain Pond and Green's Pond, between Great
Mountain and Green Mountain, are surrounded by rock and their level
has been raised several feet by artificial dams. Great Mountain Pond
is at least 50 feet above the level of Green Pond and separated from
it by a rock ridge (fig. 2).