148 Feather stonhaugJi's Geological Report. 



interrupted state of these masses, and the numerous boulders 

 found east of this formation, show the nature of the force re- 

 quired to tear up these unstratified masses from the valley, 

 and transport them to so great a distance. The sandy bed of 

 the river about here was covered with living unios. At one 

 point, called by the Nacotahs Hahhah, or the Cascade, the 

 granite stretched almost across the river, and made a fall suf- 

 ficient to oblige us to unlade the canoe. The fall here throws 

 an eddy on the right bank, which has worn out a basin about 

 fifty yards by forty, and a broad ledge of granite is formed, 

 about one hundred yards long and twenty wide, sloping to the 

 southeast. The bed of the river is thus restricted to a passage 

 of about thirty-five yards wide. South of this are numerous 

 rugged granite hills. In this granitic country the bends of 

 the river become short, the water being turned away by the 

 rocks. Three or four miles beyond this point the river is 

 almost choked up with masses of granite, at a place called 

 Patterson's rapids, from a trader of that name who once win- 

 tered there. There is, in fact, no rapid at all; the progress 

 however becomes difficult, and much care is required in get- 

 ting a birch-bark canoe through this part of the river. I had 

 come about one thousand miles in mine, and it had hitherto 

 required very little repairs. An accident would have been a 

 serious embarrassment, as there is no birch in that part of the 

 country, and the Nacotahs do not, like the Chippeways, use 

 canoes made of its bark. 



Beyond Patterson's rapids the prairie-grounds come down 

 to the banks of the river without a tree. There may be said 

 to be two kinds of prairie : the alluvial bottom, a rich black 

 soil, with wild grass from four to six feet high, sometimes a 

 mile in breadth, and thrown up into innumerable small hil- 

 locks by the moles of the country ; and then the upland prairie, 

 forming the common table-land of the region, less rich than the 

 other, but good soil, generally with low coarse grass, and the 

 horizon uninterrupted by a tree. On the upland prairies here, 



