124. Bench lands and fruit.—When moun tain glaciers covered some of the Rocky Mountains and reached down to the plains, many of the smaller mountain valleys were lakes. Some of these glacial lakes were filled with sand and earth that was washed down from the hills. Since the glaciers disappeared, the streams have cut valleys in these filled-up lake beds, leaving step-like land called ter races or benches (Fig. 123). Bench land makes very fine farms. It is level, smooth, and free from stones, and the good soil is many feet deep. Many of the benches can be irrigated by water from mountain streams. In some of the valleys, orchards of peaches, apples, and cherries have been planted; in others, hay and grain are raised. In some valleys there is not enough water for irriga tion, but wheat is grown by dry farming (Sec. 108).
125. Crop rotation.—One irrigated Colo rado bench farm has the following system: first year, potatoes; second year, wheat; third year, barley. After the barley, al falfa is sown, which makes hay during the fourth, fifth, and sixth years. In the seventh year the land is again plowed, and the rotation begins with potatoes. The tem perature of the mountain valley is just right for potatoes, and there is plenty of water, so that an acre of land very often yields 400 A bushels. The potatoes are of fine quality for hotel use. The wheat goes to market; the barley and alfalfa fatten thousands of lambs, brought in from the ranches, before being sent to Chicago, Omaha and Kansas City packing houses.
126. Sheep and cattle.— The sheep from the Rocky Mountain region are more valuable than all the other craps that are sold. When summer dries the grass upon the lower lands to the east and the west, the sheep herders with their dogs and pack horses drive the flocks up on the mountain. There the sheep pas
ture in the open valleys and browse through the forests, and even go to the grass lands above the tree line, where there are large areas of summer pasture. In the autumn the sheep eat the barley and alfalfa of the valley farms; thus these crops go to market in the cheapest way. (Sec. 75.) Many cattle also are pastured in this region.
127. Future.—Tell about the future of the town that mines gold, silver, or copper (Sec. 119); of the town that ships lumber and wood-pulp for paper-making (Sec. 121). The Rocky Mountain waterfalls can furnish power for many cities. Already on a railroad going to Seattle from Chicago, electricity from water power is used for 440 miles on the steep grades in the mountains.
If the needs of our people make it necessary to use fully the resources of this region, we may expect the national and private forests to be carefully protected from fire, so that they may regularly yield harvests of wood. Many lower slopes as well as higher slopes can be pastured; the valleys can be made into orchards, or intensively cultivated in vegetables, potatoes, wheat, barley, oats, and alfalfa. Some reservoirs have been built to hold water in the mountain valleys until the farmers want it to irrigate the plains below. Some day nearly all the water of the Rocky Mountains may thus be held until the season comes when it is needed for crops. On its way down to the plains it can turn water wheels, make power for lighting and even heating houses, and run factories and rail roads for two or three hundred miles around. There will be another advantage because the dams will prevent floods.