PLATE LXIX. 



COOK COUNTY, 1899. U. S. GRANT. 







The surface of this county is rough and hilly, but is divided into more or less 

 evident and continuous ridges and valleys that extend, with the strike of the under- 

 lying rocks, east and west in the north, and more northeast and southwest in the 

 south. This is a feature that becomes more and more pronounced toward the east, 

 and almost fades out toward the west. Besides this east-and-west trend of the minor 

 topography there are greater contours which also run in the same direction, viz.: 

 (a) The lakeward slope, from two to four miles wide, which descends abruptly from 

 200 to 500 feet from the summits of the Sawteeth mountains to the level of lake 

 Superior. In the hill range which limits this slope on the north are Carlton peak 

 and mount Josephine, the former 927 feet and the latter 703 feet above lake Superior. 

 The summits of this hill range show, when viewed from the east, a singular serrate 

 outline, and hence the name Sawteeth mountains. This range is composed primarily 

 of the Beaver Bay diabase, (b) The belt of the Highland moraine and attendant 

 gravels, which is comparatively smooth, whether considered as a morainic surface or 

 a rock formation. This extends to a line which runs approximately from the Pigeon 

 river a few miles south of South Fowl lake to the vicinity of Elephant lake, and 

 thence a little south of west to the west line of the county. North of this is (c) the 

 range of the Misquah hills, containing the highest land in the state (2,230 feet), com- 

 posed mainly of red granitic rock. This belt, as a topographic feature, does not 

 entirely cross the county, but fades out toward the east, and turns toward the south- 

 west toward the west. This range contains also the peaks known as Brule and 

 Eagle mountains, (d) Northward from the belt of red rock is a belt of gabbro, which 

 is less rough, but consists of massive east-west swells alternating with flat tracts. 

 These alternations appear to be due to the projection of gabbro' sills into the Ani- 

 mikie, the Animikie itself being hid by the accidents of the intrusion and by surface 

 materials. This belt is not continued to the Pigeon river, but runs to a point in 

 T. 64 1 E. (e) Next north of this is the Animikie province, which is probably the 

 same in substructure as the last, but differs in having the Animikie with its intrusive 

 sills separately identifiable. Here the Animikie exists in the form of monoclines from 

 100 to 500 feet high, dipping to the south. The northward face of each hill is steep, 

 even nearly vertical, capped by one of the sills of igneous rock, while the southward 

 slope is gradual, and usually consists, but not invariably, of the upper surface of the 

 igneous rock. These monoclines are sometimes five to eight miles long, but they are 

 grouped en echelon, overlapping at each end. In the valleys between them are the 



