458 CHARLES EMERSON PEET 



Through the clay on the plain high hills rise to levels beyond that 

 reached by the waters in which the clay accumulated. These hills 

 are drift- covered, and the rock outcrops frequently. Other lower 

 hills, which sometimes have the form of ridges, have rock cores, are 

 till-covered, and are mantled by the clay so as to subdue the original 

 irregularities of the rock and drift. 



WEST SIDE OF LAKE CHAMPLAIN. 



While this plain has its widest extent in the southern Champlain 

 Valley on the east side of the lake, it has been most studied on the 

 west side. From Ticonderoga to Port Kent the plain is not more 

 than 3 miles wide at any point, and contracts and 'expands as the 

 mountains approach or recede from the lake shore. The mountains 

 approach close to the shore just south of Crown Point, both north and 

 south of Port Henry, south of Whallonsburg, and north of Wills- 

 boro. They recede from the shore, near Ticonderoga, at Crown Point, 

 from a few miles north of Port Henry, to Westport, and again from 

 several miles south of Willsboro to a few miles north of that place. 

 North of Port Kent the plain widens out continually to the national 

 boundary. In its lower eastern part clay prevails at the surface, 

 except along the streams. In the higher western part till frequently 

 covers the surface. (See Figs. i8 and i for places mentioned.) 



Gravel plateaus and deltas — upper and lower series. — On approach 

 to the higher land the plain ends abruptly against the drift-covered 

 slopes or in gravel plateaus analogous to those in the Hudson Valley. 

 Near the rivers the plain gives place to a series of deltas and gravel 

 ridges, which are grouped into two series — an upper and a lower, with 

 a space of about 120 feet between the series. The upper series has 

 a range of about 80-100 feet at the north and a greater range at the 

 south. These gravel plateaus and deltas are, on the whole, higher 

 at the north than at the south, but there are exceptions. Their ele- 

 vations are as follows: Street Road gravel plateau, 540; delta, 320- 

 340. Delta on Bouquet River, 460-480; 400 (?). North Branch 

 Bouquet River near Tower's Forge, 460-80; 400 (?); near Reber, 

 440-60. Ausable River, 580-600 (?); 500. Saranac River, 640 

 (?); 520-40. The top of the Street Road 540-foot plateau may be 

 higher than the level reached by the standing water. The lower series 



