164 COPPER-BEARING ROCKS OF LAKE SUPERIOR. 
extremity lies not far from the middle of Lake Superior, being in air line 
distances 170.5 miles from Sault Sainte Marie, 212 from Duluth, 60 miles from 
Isle Royale, 38 miles from the south coast in a southerly direction, and 68 
miles from the same coast in a 8. 17° E. direction. 
From the head of Béte Grise Bay eastward the entire width of Ke- 
weenaw Point is made up of bold ridges. Further west, however, the 
ridges that form the northern and northwestern side are bordered on the 
south by a belt of flat country, which extends in the neighborhood of Port- 
age Lake to a width of some 10 miles, and at the head of Keweenaw 
Bay to a much greater width. This flat expanse rises to only inconsiderable 
elevations above the lake level, and ends abruptly against the high land on 
the north and northwest. Three lakes of some size, La Belle, Gratiot and 
Torch, lie in this low area just below the south face of the high land, while 
Portage Lake consists of a wide portion in the low land and a narrow exten- 
sion cutting entirely through the high land. 
East of Gratiot River, the higher portion of Keweenaw Point is made 
up of a series of sharp and narrow ridges lying parallel with the curving 
trends of the outer coast line, and coinciding perfectly with the trends of 
the strata. A line running directly northward across the point from Lac La 
Belle will cross four of these ridges. On the north shore of this lake the 
Bohemian Range rises abruptly to a height of over 850 feet. About a mile 
further north this range sinks rapidly for another mile to the valley of the 
Little Montreal River, which the line crosses at an elevation of 300 feet 
above Lake Superior. A little more than a mile beyond the river is met 
the bold southern cliff of the Greenstone Range, along whose southern 
foot are strung for more than twenty miles the active and abandoned 
vein mines that gave this district its reputation in former years. The Green- 
stone Range on this line rises to between 550 and 600 feet above lake level. 
Its northern face is a gradual slope conforming with the dip of the strata. 
The next depression is crossed at 44 miles, altitude 440 feet; at 54 miles 
the “‘ Great Conglomerate” ridge—altitude 700 feet—is crossed; and at 53 
miles the next valley—altitude 90 feet. The next or ‘‘ North Trap” ridge, the 
northernmost of the series, is broken down where the line crosses it at 64 
miles, but 2 miles to the east it reaches an altitude of over 700 feet. The 
