RED RIVER OF THE NORTH. 177 
by the name of Otter Tail River. The colour of the waters of Red River proper, 
also shows the origin of the name; they are of a reddish-brown cast, and contrast 
strongly with the whitish, milky appearance of the stream coming from Otter Tail 
Lake, and which henceforth assumes a darker hue. The distance by water from 
Otter Tail Lake to the Red Fork, we estimated at three hundred and seventy to 
three hundred and eighty miles. 
The soil adjacent to the main stream, from latitude 46° 30’ to Pembina, is of an 
argillaceous character. Near its confluence with the Red Fork, in latitude 47° 55’, 
it is so stiff, that in drying, it cracks, and bakes together. It seems to be’ congenial 
to the ash, which tree attains here a large size. Cottonwood timber also makes 
its appearance in this vicinity. 
In latitude 47° 54’, we passed on the right a spring, having a saline taste. Its 
water gave, with nitrate of silver, a precipitate not wholly soluble in nitric acid, 
and partially soluble in ammonia, indicating the presence of chlorides. 
Below the mouth of the Red Fork, we observed several strong chalybeate springs, 
oozing from the clay-banks. Here also is found evidence of the power of the ice 
on this river during the winter season. Fifteen, eighteen, and even twenty feet 
above the level of the river, in July, we observed the trees on the brink of the 
river, either barked or deeply cut into, and even entirely severed across. 
Unios are very abundant in this part of Red River. The most common are 
Unio quadrulus, U. alatus, U. crassus, U. plicatus, and U. gibbosus. 
In latitude 48° 23’, on the afternoon of the 2d of July, the temperature of the 
water was found to be 69°, while that of the air at the same time, in the shade, 
was 64°. In latitude 48° 37’, on the 4th of July, the temperature of the water was 
70°, at three Pp. M.; that of the air was 78°, in the shade, and in the sunshine, 
86°. The stream is here about three hundred feet wide. 
The mouth of Turtle River is, according to our observations, in latitude 48° 9’; 
that of Big Saline, in 48° 23’ 25”; and that of Two River, in 48° 50’. 
In the forenoon of the 5th of July, we discovered signs of civilization,—the trees 
chopped with the axe. At noon of the same day, we descried, from an elevated 
position, a log habitation, and at two in the afternoon, reached the mouth of Pem- 
bina River, where Mr. Sibley’s American Trading-Post, in charge of Mr. Kittson, is 
situated. This is about two miles south of the United States line, being in latitude 
48° 58’, just at the head of the settlements on Red River, which extend for about 
sixty miles below. 
The total distance from Otter Tail Lake to the mouth of Pembina River, by the 
course of the stream, was estimated at five hundred and twenty-five miles. 
Except near the Grand Rapids, no rocks are to be seen in situ in the whole of 
this distance. For more than four hundred miles of the latter part of our route, 
the soil is underlaid by a stiff, light gray, or ash-coloured clay, which exten 
beneath the level of the water. Occasionally, a few fragments of limestone, similar 
to that which we found in place at the Rapids, were discovered among the erratics. 
Both geologically and physically, it is a country of great sameness and flatness, 
without the least indication of its containing minerals of any value, except salt, 
which may be crystallized out of the saline springs. The same remark will apply 
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