Canadian Af/ricultui-e. 
225 
patches of eiHoiescent salts, which present a marked contrast 
with the crimson tufts of the marsh samphire, Salicornia, 
fringing the border. Besides the smaller sheets of water, there 
are much larger saline lakes, such as the Old Wives' Lakes, 
which are persistent. The Missouri Coteau is about 400 miles 
west of Winnipeg, and fringes the eastern margin of the third 
and highest prairie steppe, which extends, with a gentle ascent 
westward, to the base of the Rocky Mountains. 
The lowest and most eastern prairie steppe is largely iden- 
tical with, though broader than, the Red River valley. The 
floor of this valley is entirely of alluvial origin, and consists 
chiefly of the sediments of a great lake of post-glacial age, com- 
prising exceedingly fine silt, covered by black vegetable mould. 
The vailey is about 40 miles wide, and extends along either 
side of the river from north to south of the province of Mani- 
toba. Its surface is perfectly flat and undiversified, " the 
most absolutely level prairie region of America." 
From the western boundary of the Red River valley to the 
foot of the Rocky Mountains, the distance across the second and 
third prairie steppes is about 700 miles. The surface of the 
second prairie steppe is less even than that of the Red River 
valley, and is covered with thick deposits of drift, consisting 
chiefly of detritus worn from the soft underlying rocks, but 
mingled with other mineral rubbish transported from a distance. 
From the prairie level there arise in certain localities low hills, 
such as Turtle Mountain and the Touchwood Hills, composed 
of accumulations of drift materials similar to those of the Mis- 
souri Coteau. Turtle Mountain nowhere attains a height of 
more than 500 feet above the prairie. It is a region of broken 
hilly ground about 20 miles square, is thickly wooded, and 
hence presents a marked contrast to the general features of the 
prairie. As a rule, the hilly regions composed of gravel are 
wooded ; whereas the finer material of the plains has a grass- 
covered surface, except in some places along the sides of 
streams where timber also srows. 
O 
The third steppe, lying west of the Coteau, has a much thinner 
covering of drift deposits, a good deal of which consists of frag- 
ments of quartzite from the Rocky Mountains. Its eastern part 
presents in places thick deposits of true till or boulder clay. 
Its surface is more worn and diversified than is the case with 
the first and second steppes, and, as the Rockies are approached, 
it is found to consist of fragments of quartzite with softer shaly 
and slaty rocks and limestone. In various localities boulders 
are numerous, and some of these have been used in modern 
times by the buffalo as rubbing-stones, and are surrounded by 
basin-shaped depressions formed by the feet of these animals : — 
VOL. xxr. — s. s. Q 
