One of the remarkable characteristics of the Montana mountains is their great regularity and smoothness of contour. It is probable that ice action during the glacial period may have planed off the irregularities, so characteristic of the elsewhere rugged outline of the Rocky Mountains. Between these symmetrical ranges of mountains lie the broad and fertile valleys before referred to. These are generally valleys of construction, and in some former geologic period were occupied by lakes whose beds have since been drained by the streams, as they cut their way out of the mountains.
It is the extensive deposits from the ancient lakes which give to these valleys their fertile soils, while the unusual mildness of their climate is largely due to the fact that they are seldom over 5,000 feet in altitude, and the high mountains surrounding them shelter them from the severe winds which, sweeping over the plains of Dakota, become the much dreaded "blizzards."
East of the Tongue River and north of the Yellowstone and Missouri Rivers, the level bench lands are everywhere below 3,500 feet in elevation, and often below 2,500 feet, and are very dry and devoid of water, though covered by an abundant growth of fine bunch grass. These bench lands are traversed by a few narrow, deep "couleés" or "washes" having bluff banks 50 to 300 feet high, dry during most of the year, though roaring torrents in the early spring months.
It is on these bench lands that irrigation will find its greatest field, for here is a comparatively mild climate owing to the low altitude, and here the soil is fertile, warm and deep.
AREA AND KINDS OF LANDS.
The total area of Montana is 146,080 square miles, or 93,491,200 acres. Of this vast empire 31,373,000 acres or about one-third of the whole is agricultural land, while of this 18,157,000 acres or a little less than one-fifth of the entire area is irrigable land, so classified not only because it will, if provided with water, raise profitable crops, but also because, in my opinion, water can with proper management be provided for it.
Of the total area of the State only about 1,200,000 acres or less than one-sixteenth of the irrigable area may be easily cultivated, by this I do not mean that this whole amount is now reclaimed, but that it may with the means liable to be employed by private parties with limited capital, be readily brought under cultivation by the same methods by which most of the lands in Montana are now irrigated.
The amount of land actually under cultivation, according to the assessment of 1888, was 348,070 acres, and this should probably be increased by about one-half, since the farmers doubtless greatly underestimated the amounts of their cultivated lands to the assessor: perhaps then, 500,000 acres under cultivation would be nearer the truth.
It is estimated that three-fourths of the remaining 75,000,000 acres not classed above as irrigable, or say 55,000,000 acres, which is nearly two-thirds of the total area of the State, will, with the increased facilities for watering live stock and for domestic use offered by the highest state of irrigation development, become valuable as grazing land, since it is naturally covered with an abundant growth of bunch grass, and only needs better facilities for watering and for the establishment of home farms, to cause it to be entirely occupied for grazing purposes.
Nearly, or quite all, of the lands above classified as agricultural and pasture lands, are now covered with an abundant growth of bunch grass, occasional patches of sage brush or prickly pear, and devoid of any timber other than patches of willows and cottonwoods along the streams, or a few isolated clumps of scrub pines and junipers on the highest lands.