No. 30.] ROCKY RIVER. . 2? 



a small stream draining into the Housatonic. Accordingly Rocky 

 River should be found cutting its bed where it crosses the former 

 divide. It seems reasonable to regard the gorge half-way 

 between Jerusalem bridge and Housatonic River as approx- 

 imately the position of the preglacial divide and to consider the 

 small flat area to the north of Jerusalem bridge as a flood plain 

 on softer rock, worn down as low as the outcrops of more 

 resistant rock occurring farther down the valley will permit. 

 The reversal of the river may account for the sudden transition 

 from a flat-bottomed valley to a rocky gorge ; and for the abrupt 

 change in the profile, bringing the steepest part of the river near 

 its mouth. The increased volume of water flowing through the 

 channel since glacial time has plainly cut down the bed of the 

 ravine between Jerusalem and the river's mouth, but the channel 

 is still far from being graded. 



THE NEVERSINK-DANBURY VALLEY. 



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 north- 

 east 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 south- 

 ern 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. 



