Colorado's basic topography can be visualized by dividing the state into vertical thirds: The eastern part is plains; the midsection is high mountains; and the western third is mesa land.
That's a broad simplification, of course. The central Rockies, though they cover six times the mountain area of Switzerland, are a series of high ranges running roughly north-south. East of the Continental Divide, the primary river systems are the South Platte, Arkansas, and Rio Grande, all flowing toward the Gulf of Mexico. The westward-flowing Colorado River system dominates the western part of the state, with tributary networks including the Gunnison, Dolores, and Yampa-Green rivers. In most cases, these rivers are not broad bodies of water like the Ohio or Mississippi, but streams heavy with spring and summer snowmelt, which are reduced to mere trickles during much of the year by the demands of farm and ranch irrigation. Besides agricultural use, they provide life-giving water to wildlife and offer wonderful opportunities for rafting and fishing.
The forested mountains are essential to retaining precious water for the lowlands. Eleven national forests comprise 15 million acres, and there are 8 million acres controlled by the Bureau of Land Management; these are also open for public recreation. Another half million acres are within national parks, monuments, and recreation areas managed by the National Park Service. In addition to all this, Colorado has more than 40 state parks.
Colorado's name, Spanish for "red," derives from the state's red soil and rocks. Some of the sandstone agglomerates have become attractions in their own right, such as Red Rocks Amphitheater west of Denver and the startling Garden of the Gods in Colorado Springs.
Of Colorado's 4.3 million people, more than three-quarters of them live along the Front Range, the I-25 corridor, where the plains meet the mountains. Denver, the state capital, has a population just over 550,000, with another million in the metropolitan area. Colorado Springs has the second largest population, with just over 360,000 residents.
