160 FORMATIONS OF THE INTERIOR 
informed us that the waters of the lake flow both ways from it: from its northeast 
end, towards the waters of Lake Superior; from its southwest extremity, towards 
the tributaries of the Mississippi. The appearance which it presents, seen from the 
southwest end, where the portage trail strikes it, is represented in the accompany- 
ing illustration. . 
The only living things which we noticed about these lakes, except a couple of 
Indians, who happened to be travelling the same route as ourselves, were several 
northern divers, Colymbus glacialis, whose shrill and peculiar cry rung through the 
solitude, at one time resembling the screaming of children in the distance, at others, 
imitating the sound of loud, convulsive laughter. 
LONG LAKE. 
As Colonel Whittlesey’s Report gives a full account of the district bordering on 
Lake Superior, and extending as far back as the principal water-shed, on which 
Long Lake is situated, it would be superfluous to make any further remarks here 
on that region of country. 
In continuation of further details regarding the interior of Wisconsin, I proceed, 
therefore, to the description of the Valley of the St. Croix, from the source of that 
stream to its Falls, where, as we have heretofore stated, the Protozoic sandstones, 
treated of in Chapter I., emerge from beneath the northern drift. 
The portage trail which leads from the head waters of the Bois Brulé to 
those of the St. Croix, passes on the summit-level a ridge of drift, which is one 
hundred and twenty feet above Lake St. Croix, in which the stream of the same 
