Geography of Colorado
The Rocky Mountains within Colorado contain 54 peaks that are 14,000 feet (4270 m) or higher, known as fourteeners. The mountains are timbered with conifers and aspen to the tree line, at an elevation of about 12,000 feet (3,650 m) in southern Colorado to about 10,500 feet (3,200 m) in northern Colorado; above this only alpine vegetation grows. The Rockies are snow-covered only in the winter; most snow melts by mid-August with the exception of a few small glaciers. The Colorado Mineral Belt, stretching from the San Juan Mountains in the southwest to Boulder and Central City on the front range, contains most of the historic gold and silver mining districts of Colorado.
Western United States
Beyond the deserts lie the Rocky Mountains. In the north, they run almost immediately east of the Cascade Range, so that the desert region is only a few miles wide by the time one reaches the Canada–US border. The Rockies are hundreds of miles (kilometers) wide, and run uninterrupted from New Mexico to Alaska. The Rocky Mountain Region is the highest overall area of the United States, with an average elevation of above . The tallest peaks of the Rockies, 54 of which are over , are found in central and western Colorado. East of the Rocky Mountains is the Great Plains, the western portions (for example, the eastern half of Colorado) of which are generally considered to be part of the western United States.