500 NEW YORK STATE MUSEUM 



Except locally, the present stream valleys were also preglacial 

 stream valleys, and the principal modifications in the drainage pro- 

 duced by the ice, in addition to the formation of lakes, were in 

 shifting the divides. A moment's inspection of the topographic 

 map suffices to show that many of the divides thereon are of the 

 most trivial character, and are unstable. A drift-filled valley less 

 than a mile long is all that separates Upper Saranac lake and Stony 

 Creek pond, whose water level is 26 feet lower and which outlets 

 by a sluggish stream into the Raquette river just above Axton. The 

 preglacial drainage here would seem most likely to be that of a west- 

 flowing strearh in the Ampersand brook and Raquette valleys, 

 with a tributary from the south in the present Raquette valley 

 whose source was at Raquette falls, and another tributary from 

 the north in the Upper Saranac lake valley. The Raquette has 

 been a rapidly aggrading stream from below Raquette falls to 

 Tupper lake, but shows rapids and falls a few miles below where it 

 is out of its old channel. 



The divide between Long lake and Round pond is less than 20 

 feet above the water level of the former and is a low drift divide. 

 The waters of Catlin lake are ^^ feet below those of Long lake, 

 and from it there is a modern water route to the Hudson. There is 

 similarly a valley across to the Hudson drainage commencing 

 near Long Lake village, on the Blue Mountain quadrangle, which 

 is a drift-blocked channel, though with a greater drift altitude 

 than in the previous case. It would seem that one or the other of 

 these valleys was the outlet for the preglacial drainage of the Long 

 lake valley, above it the water flowing north and below it flowing 

 south, the divide being at Raquette falls; or in other words the 

 preglacial divide between the Hudson and Raquette waters was 

 here. Abundant similar examples of modern divides of the most 

 trivial character and composed of glacial drift can be seen on the 

 neighboring quadrangles. 



The immediate district is up near the main watershed of the 

 region. Lower down in their courses the main streams are out of 

 their preglacial channels here and there and are held up by the 

 rock barriers developed in these new courses. Owing to the slow 

 rate of progress in cutting through these the headwater portions of 

 the drainage channels have slight fall and little cutting power, 

 and divide shifting must in the main be delayed until these lower 

 portions of the streams have deepened their channels. 



