414 THE GLACIAL LAKE AGASSIZ. 



CAMPBELL SHORES IN NOKTH DAKOTA 



(PLATES XXVII-XXX.) 



On the west side of Lake Agassiz one of the Campbell shore-lines 

 begins to be marked by a beach ridge in the northwest corner of section 5, 

 township 128, range 47, South Dakota, where it lies about 15 rods east of 

 L. H. Eldred's house, running in a north-northwesterly course and imme- 

 diately passing into North Dakota. The crest of this gi-avel ridge is 988 

 to 990 feet above the sea, with slopes that fall 12 feet to the east and 3 to 

 6 feet to the west, the sm-face on each side being till. 



The Minneapolis and Paciiic Railway and the Aberdeen Branch of the 

 Great Northern Railway cross three Campbell beaches west of the Bois des 

 Sioux. Wider spaces separate the shore-lines here than elsewhere, because 

 the land is very nearly level and the lake had only a slight depth to a dis- 

 tance of several miles offshore. When the district was uplifted or the level 

 of the water fell away even 4 or 5 feet, the emerging belt varied from 1 

 to 3 miles in breadth. The most eastern of these beaches, lying within a 

 half mile east of Fairmount, fonns small, in-egular ridges, with crests at 



979 to 984 feet. The next, passing by De Villo station, has an elevation 

 of 987 feet; and the third, which is the continuation of the ridge at Mr. 

 Eldred's, runs northwestward nearly tbrough the center of De Villo Town- 

 ship, rising 5 feet above the general level, with its crest at 993 feet. But 

 probably the earliest Campbell stage of Lake Agassiz here is represented 

 by a line of dunes only 3 to 5 feet in height, with crests at 995 to 997 feet, 

 crossed by these railways about 2 miles west of Oswald and Sonora. The 

 lake levels thus indicated range from 992 feet, very nearly, downward to 



980 feet, or perhaps 2 or 3 feet lower. 



Continuing northwestward, these shores converge, on account of the 

 increasing rate of westward ascent of the surface, as they approach the Shey- 

 enne delta. They cross the Northern Pacific, Fergus Falls and Black Hills 

 Raih-oad on the very gentle southeastward slope of the delta about 2 miles 

 west of Mooreton, but are not definitely traceable there. Eight miles far- 

 ther north the Campbell and upper McCauleyville shores begin to be 

 marked by the escarpment or steep slope, descending eastward 20 to 50 

 feet within about a mile, which forms the eastern border of the principal 



