THE WINNIPEG BASIN, as already defined, has an area of about 275,000 square miles. In general appearance it is a great plain sloping gently down to the north and east ; but it may be sub divided into regions known respectively as the first, second, and third prairie steppes or slopes. The first of these is bounded on the east by the Laurentian country, and on the west by a line of heights which cross the international boundary about forty miles west of the Red River, and run in a north-westerly direction. This slope has an average elevation of about 800 feet and an area of about 30,000 square miles. It belonged to the bed of the glacial Lake Agassiz, and the glacial deposits with which it is covered con stitute a stiff, compact, " unctuous " clay of great fertility. The second prairie slope is bounded on the west by a height known as the Missouri C8teau, which crosses the international boundary about 250 miles west of the previous escarpment, and like it runs in a north-westerly direction. This slope, which consists chiefly of rolling prairie, is drift-covered ; it has an average elevation of 1,600 feet, and an area of about 100,000 square miles. The third slope, with a breadth of 465 miles at the international boundary, rises from a height of 2,000 feet in the east to one of 4,000 feet along the foothills of the Rocky Mountains. The plains, which are drift covered, are generally more undulating in character than on the first and second slopes, and are broken up in places by hilly regions.
The rainfall over the eastern and northern parts of the Winnipeg Basin varies from 15 to 20 inches per year, but, in the south-west, there is a large area where it is less, and where, consequently, conditions are much less favourable for arable farming. The southern parts of the first and second slopes constitute at present the wheat-producing region of the Winnipeg Basin. The great stretches of flat prairie, which formed the bed of Lake Agassiz, with their fertile soils, sufficient precipitation, high summer tem peratures, and great facilities for easy cultivation and communica tion, make one of the richest agricultural regions of the world.
The corresponding part of the middle slope, though somewhat drier, more especially in the west, has, with the advent of American farmers accustomed to less humid conditions than prevail along the Atlantic seaboard, made rapid progress, and now contains more than half of the wheat lands of the Winnipeg Basin. Throughout these districts wheat may be regarded as a certain crop, and the average yield is relatively high, being about 18 bushels per acre.
In the northern parts of the eastern and middle slopes the land is more broken in character, the drainage in places is bad, and the climate is less favourable. Considerable areas, moreover, on the eastern slope especially, are occupied by communities of Russians and Galicians, whose knowledge of agriculture is somewhat primitive, and who farm for sustenance rather than for export. Mixed farming, accordingly, prevails here to a much greater extent than in the south.
On the third prairie slope, which contains the south-western part of Saskatchewan and the southern part of Alberta, conditions, especially in the semi-arid region in the south, are at present less favourable to agriculture. The semi-arid area " is bounded on the south by the international boundary, on the east and north by a line commencing at the intersection of long. 102° W. with the international boundary, and running from thence north-westerly to lat. 51° 30', and thence west to the Rocky Mountains. This portion of the territories contains about 80,000 square miles." In this district, fall wheat may be grown in favoured localities without irrigation, but, generally speaking, some modifications in the usual methods of farming are necessary to ensure a certain crop. To the east_and north of the semi-arid region wheat may be grown over large areas, although in some parts, more especially in the north west, oats form a more suitable crop, and the general tendency is to the development of mixed farming.