hese
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).

HISTORY OF THE GLACIAL DEPOSITS

A tongue of the glacier is supposed to have lain in the valley of the
Umpog and gradually retreated northward after the ice had disappeared
from the uplands on either side. The ridge of intermediate height
built of limestone and schist, which extends down the middle of the
valley, was probably covered by ice for some time after the glacier
had left the highlands.

When the mountain mass extending from Pine Mountain to Town Hill west
of the Umpog Basin and the granite hills to the east terminating in
Shelter Rock are considered in their relation to the movement of the
ice, it is apparent that the valley of the Umpog must have been the
most direct and lowest outlet for glacial streams south of Danbury.
These streams built up the terraces and other deposits of stratified
drift which occupy the valley between Bethel and West Redding.

The heavy deposits of till near West Redding mark a halt in the
retreating glacier. The boulders at this point are large and numerous,
and kames and gravel ridges were formed. The deposits at the divide,
supposed to have formed a glacial dam which reversed the Umpog,[14]
are much less heavy than at points short distances north and south of
the water parting.

As the ice retreated, sand and gravel in the form of terraces
accumulated along the margin of the Umpog valley, where the drainage
was concentrated in the spaces left by the melting of the ice lobe
from the hillside. Among these deposits are the bodies of sand and
gravel which lie against the rocky hillslopes most of the way from the