The Cordilleran system on the western side of the continent is lofty, broad and complicated, with heavy forests near the north-west coast, but elsewhere with trees only on the higher ranges below the Alpine region, and with treeless or desert intermont valleys, plateaus and basins, very arid in the south-west.
It was chiefly the mineral wealth of the Cordilleran region, first developed on the far Pacific slope, and later in many parts of the inner mountain ranges, that urged pioneers across the dry plains into the apparently inhospitable mountain region; there the adventurous new-corners rapidly worked out one mining district after another, exhausting and abandoning the smaller camps to early decay and rushing in feverish excitement to new-found river fields, but establishing important centres of varied industries in the more important mining districts.
The Cordilleran Region.From the western border of the Great Plains to the Pacific coast, there is a vast elevated area, occupied by mountains, plateaus and intermont plains.
The descending winds on the eastern slopes of the ranges are frequently warm and dry, to the point of resembling the Fhn winds of the Alps; such winds are known in the Cordilleran region as Chinook winds.
Discoveries in other Cordilleran territories, notably in Montana and Idaho, made up, however, in part for the deficiency of California, so that in I 860 the total amount of gold produced in the United States was estimated at not less than $45,000,000.