Age of the St. Croix Dalles— Upbam. 347 
AGE OF THE ST. CROIX DALLES. 
By Warren Upham, St. Paul, Minn. 
The most beautiful gem of scenery in the states of 
Minnesota and Wisconsin is the Upper Dalles of the St. 
Croix river, which forms a part of the boundary between 
these states. By legislative acts of each state, the land on 
both sides of the river, adjoining this picturesque rock 
gorge, has been made an Interstate Park, for public enjoy- 
ment and instruction, similar to the International Park at 
Niagara Falls. From the "Twin Cities" of St. Paul and 
Minneapolis, and from a large surrounding region of both 
Minnesota and Wisconsin, many picnic excursions come to 
the St. Croix Dalles ; and many tourists, especially geolo- 
gists and naturalists, are attracted thither, to. see the beauti- 
ful and grand scenery of the gorge, and its wonderful 
waterworn potholes, such as in Germany and Scandinavia 
are called giants' kettles. 
Therefore much attention has been given to the 
geology of the vicinity of the Dalles, by Prof. N. H. 
Winchell and the present writer, as his assistant, on the 
Geological Survey of Minnesota ;* by Dr. C. P. Berkey, Mr. 
A. H. J^lftman, and the writer, in later papers, coming to 
the study of this area from its Minnesota side ;t by Prof. 
T. C. Chamberlin and his assistants on the Geological Sur- 
vey of Wisconsin ;t and most recently by his son, Mr. Rollin 
T. Chamberlin, who last year spent a month in examina- 
tion of the Dalles region.§ 
The last author has well described and mapped the 
deploying currents and recessional moraines of the Lake 
Superior lobe of the ice-sheet, developed during the Wis- 
* Geology of Minnesota, vol. i, 1884, pp. 126-7; vol. ii, 1888, pp. 399- 
425, with a map or Chisago, Isanti, and Anoka counties. 
t Charles P. Berkey, Geology of the St. Croix Dalles, Am. Geologist, 
vol. XX, pp. 346-383, with maps and sections, Dec, 1S97: and vol. xxi, 
pp. 139-155, and 270-294, with maps and plates. March and May, 1898. 
A. H. Elftman, The St. Croix River Valley, Am. Ueologist, vol 
xxii, pp. 58-61, July, 1898. 
Warren Upham, Pleistocene Ice and River Erosion in the St. Croix 
Valley of Minnesota and Wisconsin, Bulletin, Geol. Society or America, 
vol. xii, pp. 13-24, Nov., 1900; Giants' Kettles eroded by Moulin Torrents, 
Bulletin G. S. A., vol. xii, pp. 25-44, with a map of the Upper Dalles, 
Dec, 1900. 
t Geology of Wisconsin, vol. i, 1883, pp. 261-300, including a map 
of the Minnesota, Superior, Chippewa, Green Bay, and Michigan lobes of 
the Ice sheet, the Driftless Area, etc.; vol. iii, 1880, pp. 363-42S; and vol. 
Iv, 1882, pp. 99-159. 
S The Glacial Features of the St. Croix Dalles Region, Journal of 
Geology, vol. xiii, pp. 238-256, with three maps, April-May, 1905. 
