Colorado has the highest concentration of high mountains in the lower 48 states. Over one thousand summits top 10,000 feet, while 54 top 14,000 feet, and are affectionately known as fourteeners. These are the remaining high points of an eroded plateau. The elevation of the mountains is generally uniform, with few of the fourteeners standing out as significantly higher than the others. Most mountains have easy routes up rounded flanks, and more difficult climbs up steep rock faces. Some small glaciers exist, and snow covers the mountains from December through May, with some snow patches remaining through most of the year. The mountains are more accessible during the summer, but severe afternoon thunderstorms are common.

Wildlife is plentiful, and black bear, mountain lion, mountain goat, bighorn sheep and elk are commonly spotted on the open slopes and in the fir and aspen forests of the valleys. The mountain wilderness also includes abandoned mountain homesteads and ghost towns, remnants of the original Colorado settlers, who flocked to the region to mine gold and silver. The miners and Native Americans were the first to climb many of Colorado's 14,000-foot peaks.