ON THE SHORES i>K LARK SUPERIOR. 5 



Lake Superior are, in extensive and dense forests, where the explorer can only sec 

 a tew rods, or, perhaps, yards around him, and where there is seldom anything 

 which rises sufficiently high ahove the surface to attract the eye. 



They arc, for the most part, merely irregular depressions in the soil, trenches, pits, 

 and ca\ ities; sometimes not exceeding one foot in depth, and a few feet in diameter. 

 Thousands of persons had seen the depressions prior to 1848, who never suspected 

 that they had any connection with the arts of man; the hollows, made by large 

 trees overturned by the wind, being frequently as well marked as the ancient exca- 

 vations. Besides this, there are natural depressions in the rocks on the outcrop of 

 veins, formed by the decomposition of the minerals, that resemble the troughs of 

 the ancient miners, as they" appear after the lapse of centuries. There is not always 

 a mound or ridge along the side of the pits, for most of the broken rock was thrown 

 behind, nearly tilling up the trenches. A mound of earth is as nearly imperishable 

 as any structure we can form. Some of the tumuli of the west retain their form, 

 and even the perfection of their edges at this day. But mere pits in the earth are 

 rapidly filled up by natural processes. Some of those which have been reopened, 

 and found to have been originally- ten feet deep, are now scarcely visible. Others 

 that have a rim of earth around the borders, or a slight mound at the side, and 

 were at first very shallow, are more conspicuous at present than deep ones without 

 a border. 



There are, however, pits of such size as could not fail to surprise one at first view, 

 were not the effect destroyed by the close timber and underwood with which they 

 are surrounded. A basin-shaped cavity, 15 feet deep and 120 feet in diameter, 

 would immediately attract the eye of the explorer were it properly exposed. But 

 it is not unusual to find ten and twelve feet of decayed leaves and sticks, filling a 

 trench, and no broken rock or gravel. In such cases a fine red clay has formed 

 towards the bottom, a deposit from water, which indicates the long period of time 

 since the excavation was made. 



From the accompanying map it will be seen that the positions of the principal 

 ancient mines correspond to those which arc worked at present. There are three 1 

 groups or centres of operation in both cases, one a little below the forks of the 

 Ontonagon River, another at Portage Lake, and a third on the waters of Eagle 

 River. Other works are known to exist, and more will probably be found; but we 

 have probably discovered the most important ones within the district embraced by 

 the map. 



Although the old works are not always situated upon what would be considered 

 good veins, yet they are regarded by practical miners as pretty sure guides to valu- 

 able lodes. 



In the opening of our principal mines, we have followed in the path of our pre- 

 decessors, but with much better means of penetrating the earth to great depths. 

 The old miners performed the part of surface explorers. 



In giving detailed descriptions of the antiquities of the mining country, we shall 

 commence with those most easterly, near the extremity of Point Keweenaw, and 

 proceed along the mineral range in the order of position to the southwest. There are. 

 however, ancient works found over a much greater space than is included in the map. 



