100 GEOLOGY OF EASTERN WISCONSIN. 



has a trend of about S. 35° W. Following up the valley in this direc- 

 tion, it presents the same characteristics, bounded by an abrupt wall 

 of rock on the east, and gently sloping upward to the west. It rises 

 somewhat rapidly, so that when Lake Winnebago is reached, an eleva- 

 tion of 169^- feet, canal survey, or 162 feet, railroad survey, has been 

 attained. This lake strikingly resembles Green Bay in the nature of 

 its eastern and western shores. Its trend, however, is nearly due north 

 and south, and if we follow on in this new direction, the valley leads 

 up over the watershed between the Mississippi and St. Lawrence, ba- 

 sins, into the valley of Eock river. This extension of the Green Bay 

 valley will be noticed farther on. 



For the present, however, we are considering the diagonal valley — 

 the topographical and drainage basin — which has its extension in the 

 valley of the Upper Fox river. Like the preceding, this portion of tho 

 valley has its more abrupt slope on the south side, but this is far less 

 conspicuous than before, nor do we find the same broad, level tract on 

 the opposite side. These differences are due partly to the fact that 

 the valley, in this portion, crosses the geological formations obliquely, 

 whereas, in the lower portion, it followed their trend, and partly to 

 the fact that here the drift movement was across the valley from east- 

 ward to westward to a considerable extent. This valley undoubtedly 

 had an existence before the glacial epoch, and during that period it 

 was probably more filled than eroded. 



The Fox river, in this portion of its course, has a much less rapid 

 descent than between Lake Winnebago and Green Bay, a circumstance 

 greatly favoring its improvement and navigation. The Upper Fox 

 descends 40 feet in an air-line distance of about 60 miles, or a little 

 more than 100 miles along its meanderings, while the Lower Fox de- 

 scends 162 (1691-) feet in half that distance. 



The valley leading south from Lake Winnebago, which has been 

 alluded to as an extension of the Green Bay valley, and, as will here- 

 after be seen, is in many respects entitled to be so considered, rises 

 140 feet in 15 miles. These facts, supported as they are by many 

 others of similar import, show that the diagonal valley under consid- 

 eration is not a fanciful conception, but a well characterized, if not 

 obvious, fact. 



The commercial importance of this valley in presenting suitable 

 conditions for the establishment of water communication between the 

 Mississippi and the great lakes, has awakened a deep interest among 

 leading citizens of this and adjoining states, and public attention 

 has been so thoroughly turned- toward it, and the prospect of realiza- 

 tion is so good, and so immediate, that so far as the people of the state 



