Between Neversink Pond and Danbury extends a deep rock valley, in
places filled with drift. As has been shown, this valley was probably
occupied in preglacial time by Rocky River, which then flowed
southward. At its southern end is Still River, which flows through
Danbury from west to east.
The most important tributary of the Still rises northwest of the city,
just beyond the New York-Connecticut boundary line, and has two forks.
The northern fork, which drains East Lake, Padanaram Reservoir, and
Margerie Pond, flows along the northeast side of Clapboard Ridge. The
southern fork has two branches; the northern one includes the
reservoirs of Upper Kohanza and Lake Kohanza, while the upper waters
of the southern branch have been recently dammed to form an extensive
reservoir. On approaching the city, the northernmost fork (draining
East Lake) turns sharply out of its southeast course and flows in a
direction a little east of north. At the end of Clapboard Ridge, the
stream makes a detour around a knoll of coarse stratified drift. From
this turn until it joins Still River, a distance of about a mile, the
stream occupies a broad and partly swampy valley.
At the cemetery in this valley (fig. 1, C) are two eskers of symmetric
form, each a few hundred yards in length and trending nearly parallel
with the valley axis. East of the valley, and about 1-1/2 miles north
of the cemetery, is a broad, flat-topped ridge of till with rock
exposed at the ends, forming a barrier which doubtless existed in
preglacial time. West of the valley is a hill with rock foundation
rounded out on the northeast side by a mass of drift. The preglacial
course of Rocky River was between the outcrops at these two
localities.
Northwest of the cemetery for one and a half miles the uneven surface
is formed of till and small patches of stratified drift. In a swamp
near the north end of the cemetery is a curved esker with lobes
extending south and southwest. One mile north of this swamp is an area
of excessively coarse till containing boulders which range in diameter
from 6 to 10 feet and forming a low ridge separating two ravines, in
which head streams flowing in opposite directions. The area of coarse
till is bounded on the north by a long sinuous esker of coarse gravel
terminating in a flat fan, which is superposed on a field of fine
till. Associated with the esker is an interesting group of kames and
kettleholes, the largest kettlehole being distinguished by distinct
plant zones banding the sides of the depression.
North of the area of boulders, eskers, and kames just described lies a
swamp whose surface is 30 to 40 feet below the upper level of the kame
gravels. Soundings made by T. T. Giffen revealed the presence of 36
feet of peat and 2 feet of silt overlying firm sand, so that 70 feet
is the minimum estimate for the difference in level between the
surface of the gravels and the floor of the swamp.
Below the rocky cliffs which line the valley sides are boulders
brought by the ice from near-by ledges, and about one-half mile above
the head of the swamp are remnants of a terrace standing 20 to 30 feet
above the level of the stream. Although the terrace appears to consist
of till, it may conceal a rock floor which was cut by a former stream.
As the valley is followed toward Neversink Pond, the various features
of a till-coated, rock-floored valley are seen.
[Illustration: ~Fig. 6.~ Course of Still River. Dotted lines show the
preglacial channels.]