Rocky River begins its course as a rapid mountain brook in a rough
highland, where the mantle of till in many places is insufficient to
conceal the rock ledges (fig. 1). Near Sherman, about four miles from
its source, it enters a broad flood plain and meanders over a flat,
swampy floor which is somewhat encumbered with deposits of stratified
drift and till. Rocky hills border the valley and rise abruptly from
the lowland. The few tributaries of the river in this part of its
course are normal in direction.
About six miles below Sherman, Rocky River enters Wood Creek Swamp,
which is 5-1/2 miles long by about one mile wide and completely covers
the valley floor, extending even into tributary valleys. Within the
swamp the river is joined by Squantz Pond Brook and Wood Creek.
Tributaries to Wood Creek include Mountain Brook and the stream
passing through Barses Pond and Neversink Pond. The head of Barses
Pond is separated from the swamp only by a low ridge of till.
Neversink Pond with its inlet gorge and its long southern tributary
record significant drainage modifications, as described in the section
entitled "The Neversink-Danbury Valley."
Within and along the margin of Wood Creek Swamp, also east of Wood
Creek and at Barses Pond, are rounded, elongated ridges of till, some
of which might be called drumlins. East of Neversink Pond is the
lateral moraine shown in Pl. I. From the mouth of Wood Creek to
Jerusalem, Rocky River is a quiet stream wandering between low banks
through flat meadows, which are generally swampy almost to the foot of
the bordering hills.
Near Jerusalem bridge two small branches enter Rocky River.
Immediately north of the bridge is a level swampy area about one-half
mile in length. Where the valley closes in again, bedrock is exposed
near the stream, and beginning at a point one-half mile below (north
of) Jerusalem, Rocky River--a swift torrent choked by boulders of
great size--deserves its name.
In spite of its rapid current, however, the river is unable to move
these boulders, and for nearly three miles one can walk dry-shod on
those that lie in midstream.
At two or three places below Jerusalem, in quiet reaches above rapids,
the river has taken its first step toward making a flood plain by
building tiny beaches. One-half mile above the mouth of the river the
valley widens and on the gently rising south bank there are several
well-marked terraces about three feet in height and shaped out of
glacial material. A delta and group of small islands at the mouth of
Rocky River indicate the transporting power of the stream and the
relative weakness of the slow-moving Housatonic.