At Denver we reach the edge of the Rocky-Mountain foot-hills; the grand snow-peak of Mount Rosalie, rivalling Mont Blanc in height and majesty, though forty miles away, seems to rise just behind the town; thence southerly toward Pike's and northerly toward Long's Peak, the billowing ridges stretch away brown and bare, save where the climbing lines of sombre green mark their pine-fringed gorges, or the everlasting ice pencils their crests with an edge of opal. Still we do not leave the Plains region. We glide through the thronged streets of the growing city, cross the South Platte by a short bridge, and strike nearly due north along the edge of the mountain-range, over a broad plateau which still bears the characteristic _grama_. Not until we enter the _canon_ of the Cache-la-Poudre, a hundred miles from Denver by the road, can we consider ourselves fairly out of the Plains, and in the fifth great region of the continent, the Rocky-Mountain system of ridges and intramontane plateaus. Before we begin this portion of our journey, let us examine, in the light of that already accomplished, an assertion made early in this article to the effect that the Pacific Railroad must precede and create the business which shall support it. The consideration shall be brief as a mathematical process. The river-bottoms and divides along the Lower Republican are peculiarly suited to the raising of farm-produce. But so long as they had no avenue to a market, they might have been fertile as Paradise without alluring settlers to cultivate them. The natural advantages of a country are developed not as a matter of taste, but as a matter of profit. The crops which can be raised to best advantage in this region are the crops which without a railroad must rot on the ground. No man can be expected to settle in a new country from pure Quixotism,--and nothing but the railroad would make anything else of his expenditure of energies beyond the needs of self-support. The Plains are the natural pasture of the continent; but they have no natural fascination for the white man which can induce him to take up his residence there for cattle-breeding _en amateur_. The greatest enthusiast in butter and cheese would scarcely care to accumulate mountains of rancid firkins and boxes for the mere gratification of fancy. Access to a market is his only justification for spending a nomadic lifetime among herds, or a fortune on churns and presses. The settlement of the country must precede the birth of its industries, and the Pacific Road is the absolutely essential stimulus to such settlement.