THE NORTHERN PACIFIC ROUTE, 37 
from 90° to 105°. The mean annual precipitation is about 20 to 24 
inches, compared with 28 inches at St. Paul and 15 or 16 inches in the 
western part of the State. 
The Red River valley, including that part which lies in Canada, was 
one of the first to be explored in this part of the country. Lake 
Winnipeg, at its mouth, in Canada, was part of the great highway 
by which the French voyageurs penetrated the country west of Lake 
Superior in the early days of the trapper and trader. The earliest 
authentic record of exploration is that of Verandrye, who made an 
unsuccessful attempt to cross the continent in 1738-1742. French 
traders doubtless followed in his footsteps, but they left few if any 
records of their experiences or of the country traversed. In the 
early years of the nineteenth century David Thompson and Alexander 
Henry, of the Northwest Fur Co., pushed their way up the Red River 
valley into what is now North Dakota and Minnesota; and in 1812 
the Karl of Selkirk made the first settlement in the vicinity of Winni- 
peg. Many French traders probably found their way south into 
that part of the Red River valley lying in North Dakota, for Lewis 
and Clark mention their presence on the Missouri as early as 1804. 
Not much is known of the rocks underlying the Red River valley, 
for they are effectually concealed by the glacial drift and by the 
sediment deposited in Lake Agassiz, but their presence here and there 
has been revealed by deep drilling. The deepest well which was sunk 
near Moorhead penetrated lake sediment and glacial drift to a depth 
of 220 feet, Cretaceous shale with some sandstone for 150 feet, and 
the underlying granite to a depth of more than 1,500 feet. This 
region is therefore near the eastern edge of the great mass of Cre- 
taceous strata which extends as an unbroken sheet to the Rocky 
Mountains and which can be seen at many places along the Northern 
Pacific Railway. The sea in which these materials were laid down 
must at some stage of its existence have extended farther east than 
the Red River valley, for a few exposures of these rocks have been 
found in the valley of the Mississippi. (See route map, sheet 2, p. 26.) 
A few years ago a traveler crossing the old lake bottom just before 
the wheat harvest would have seen mile after mile of grain, which on 
a clear breezy day would have looked much like the waves rolling 
across the water, and he could almost have imagined Lake Agassiz to 
be still in existence. In recent years the crops in this region have 
become more diversified and now instead of the unbroken stand of 
wheat that stretched to the horizon line, the traveler sees interspersed 
with the wheat other grains and flax, and only here and there is the 
wheat grown in large areas. The rich black soil extends in almost 
unbroken regularity across the valley and it is under a high state of 
cultivation, even to the very edge of the railroad track. Probably 
ere are few regions in the world in which the soil is more fertile than 
