Upham.l 
142 
[May 21, 
of the North, so named to distinguish it from the Red river of Louis- 
iana, lies in the middle of the North American continent, between 
45° and 52° north latitude, and between 95° and 106° west longi- 
tude, comprising parts of Minnesota and North and South Dakota 
in the United States and of Manitoba and Assiniboia in the Domin- 
ion of Canada. Its altitude rises from lake Winnipeg, 710 feet 
above the sea, to the Riding and Duck mountains in northwestern 
Manitoba, respectively about 1,800 and 2,000 feet above this lake, 
or 2,000 and 2,700 feet above the sea, while similar elevations are 
reached on and south of the international boundary by the Turtle 
mountain, the Coteau du Missouri, and the Coteau des Prairies. 
In general the country is a smoothly undulating and rolling, or in 
portions almost perfectly flat, expanse of glacial drift, overlain on 
certain areas by lacustrine and alluvial beds. 
Along the Red river valley and on its east side in northwestern 
Minnesota, the superficial deposits are from 100 to 300 feet deep, 
and rest on Archaean gneisses and on Cambrian and Silurian lime- 
stone and sandstone strata. West of the Red river, on the plateau- 
like area stretching westward from the top of the Pembina mountain 
escarpment in North Dakota and southwestern Manitoba, the drift 
is comparatively thin, being commonly from 10 to 50 feet in depth, 
and lies upon Cretaceous shales which are penetrated about 1 ,400 
feet by artesian wells at Devil’s Lake and Jamestown. A consid- 
erable proportion of magnesian limestone boulders, gravel and de- 
tritus is present in the drift of the whole district, and westward the 
sulphates of lime, magnesia, and soda are supplied to the drift by 
its ingredient of the Cretaceous shales. The water of springs, 
streams, lakes and sloughs is therefore hard, and contains, espec- 
ially westward, much alkaline matter, favoring the growth of nu- 
merous species of plants which can thrive* only on alkaline soil. 
The low plain bordering the Red river, commonly denominated 
the Red river valley, which was covered by the deep central part 
of the glacial Lake Agassiz during the recession of the ice-sheet, 
and is now the most fertile wheat-producing district of this conti- 
nent, has a width of 40 to 50 miles and a length of about 300 miles 
from lake Traverse north to lake Winnipeg. The climate of this 
valley and of the entire basin is mostly cool and invigorating through 
the six or seven months in which the land is worked and its har- 
vest gathered. The warmest days of summer have a temperature 
