Early Man in Sortlteastern Minnesota — >>iunfz. 81 



Te^etable deposit, peat bearing on its surface spruce and tamarac 

 trees, cranberries and the peat mosses. This lake is connected with 

 a similar one, created by a dam on Pike river, which now like the 

 first is filled with peat. The depth of peat in this swamp may give 

 us data from which to calculate the period of time that has elapsed 

 since the valley was flooded. Assuming the deposit to be six feet 

 deep and that it accumulated at the rate of one inch in a hundred 

 years, we have a period of 7200 years. 



A.fter passing the divide we reach Pike river, a stream only 

 about two rods wide in Town 60, Range 15. This stream empties 

 into Vermillion lake; it has four dams on it below the one spoken 

 of above. I will describe two of them. 



The first, at the crossing of the wagon road from Duluth to 

 Lake Vermillion in Town 61, Range 15. At this point a dam of 

 bowlders has been placed across the valley, the largest of which 

 are several tons weight each. These rocks have been taken from 

 the bed of the stream above. The height of the dam does not ex- 

 ceed four feet, yet it makes the stream navigable for nine miles. 

 When w^e consider that this country in the valley of Vermillion 

 lake is perfectly paved with rocks, torn from ledges during the 

 glacial period, that these rocks occupy the hill tops, and that in 

 the excavation of the valley, of a stre im having a grade of less 

 than six feet to the mile, a stream of great volume would not even 

 move small pebbles, nor have they the slightest action on sand, we 

 should expect that the removal of the finer clays and sands would 

 give more prominence to the bowlders. Here we find a stream run- 

 ning through just such a valley as I have mentioned and for 9 

 miles one can move along in an average stage of water on a placid 

 canal. I conclude therefore, that the channel has been closed and 

 the rocks piled into these dams. About one-fourth of a mile above 

 Vermillion lake the stream falls over a ledge of altered slates. 

 Above these falls there is a rapid 500 feet in length, in which dis- 

 tance the stream falls about 12 feet. At the head of this rapid 

 the stream suddenly deepens to 10 feet and so abruptly that the 

 stones appear to have been laid up in the form of a wall. For the 

 distance of about 1500 feet above this dam the stream 

 crosses ledges of trap rocks and then opens out into a valley 

 flooded for six miles and a half or to to the foot of the next rapids. 

 If the bowlders were removed from the channel above the falls, the 

 stream would drain the valley and destroy the navigation of the 

 stream for canoes for a mile and a half. 



