I believe a dam across either fork of the Platte, at any favorable point above their junction, raising the surface of the stream six feet, at a cost not exceeding $10,000, would suffice to irrigate completely not less than fifty square miles of the valley below it, while serving at the same time to furnish power for mills and factories to a very considerable extent; for the need of Irrigation is not incessant, but generally confined to two or three months per annum, and all of the volume of the stream not needed for Irrigation could be utilized as power. Thus the valleys of the few constant water-courses of the Plains may come at an early day to employ and subsist a dense and energetic population, engaged in the successful prosecution alike of agriculture and manufactures, while belts, groves, and forests, of choice, luxuriant timber, will diversify and embellish regions now bare of trees, and but thinly covered with dead herbage from June until the following April. But, when we rise above the bluffs, and look off across the blank, bleak areas where no living water exists, the problem becomes more difficult, and its solution will doubtless be much longer postponed. To a stranger, these bleak uplands seem sterile; and, though such is not generally the fact, the presumption will repel experiments which involve a large initial outlay. The railroad companies, which now own large tracts of these lands, will be obliged either to demonstrate their value, or to incite individuals and colonists to do it by liberal concessions. As the case stands to-day, most of these lands, which would have been dear at five cents per acre before the roads were built, could not be sold at any price to actual settlers, even with the railroad in plain sight, because of the dearth of fuel and timber, and because also the means of rendering them fruitful and their cultivation profitable are out of reach of the ordinary pioneer. Hence, so long as the valleys of the living streams proffer such obvious invitations to settlement and tillage, by the aid of Irrigation, I judge that the higher and dryer plains will mainly be left to the half-savage herdsmen who rear cattle and sheep without feeding and sheltering them, by giving them the range of a quarter-section to each bullock, and submitting to the loss of a hundred head or so after each great and cold snow-storm, as an unavoidable dispensation of Providence. But in process of time even the wild herdsmen will be softened into or replaced by regular farmers, plowing and seeding for vegetables and small grains, sheltering their habitations with trees, and sending their children to school. This change involves Irrigation; and the following are among the ways in which it will be effected: