354 The American Geolofjiat. December, 1897 
20 miles south of this district, two prorniiient terrac^es with 
several minor ones are described.* The lowest of these is 70 
feet above the river. The river level is 672 feet above the sea,f 
making the elevation of the terrace 742 feet. The second of 
these Hudson terraces is 200 feet above the river, making an 
elevation of 872 feet above the sea. I do not know of any 
corresponding terraces in the St. Croix Dalles area, unless we 
may consider the 905-foot terrace, which is so prominently 
marked in the village of Taylor's Falls, as such representative. 
This, I am inclined to think, is a proper correlation. At a 
time when such a terrace must have been formed it is not 
probable that any considerable fall was encountered within 
the distance. It is reasonable to suppose that a descent 
of 30 feet between the two points would not be excessive 
for the glacial river. This terrace-like development at 905 
feet on both sides of the river is further discussed in the 
chapter on Glacial Geology. 
There is evidently no connection between tl)e 742-foot ter- 
race at Hudson, Wis.', and the terraces of this district. It is 
believed that a considerable fall was developed below the 
Dalles, where the soft sandstones were reached. If this be ac- 
cepted, it must also follow that, from the time of their begin- 
ning, the terraces above the fall would be entirely independ- 
ent of those below, not only in the matter of elevation, but 
also in the point of origin. 
There have been two other terraces noted in previous geo- 
logical reports by Mr. Upham. These extend;]; from Sec. 2 
Shaffer northward and are very pronounced terraces. Mr. 
Upham estimated them respectively 90 and 125 feet above the 
river. These estimates would indicate at this point eleva- 
tions of 830 and 865 feet above sea level. It is therefore prob- 
able that the first one of Mr. Upham's terraces corresponds to 
the 810-foot terrace of the Dalles district. The 865-foot ter- 
race has no corresponding development in the 10 miles imme- 
diately south of it, unless the 850-foot side channel mentioned 
before may be related to this stage of the St. Croix river. 
The smaller streams and their erosion effects. There are 
*Geology of Wisconsin, vol. IV, 1882, p. 134. 
tU. S. G. S., Bulletin 72. 
JMinn. Geol. and Nat. Hist. Survey, vol. 11., Final Rep., 1882, p. 117. 
