Colorado is one of only three U.S. states (with Wyoming and Utah) that have only lines of latitude and longitude for boundaries. The summit of Mount Elbert at 4401 meters (14,440 feet) elevation in Lake County is the state's highest point and the highest point in the entire Rocky Mountains. Colorado has approximately 550 mountain peaks that exceed 4000 meters (13,123 feet) elevation. Colorado is the only U.S. state that lies entirely above 1000 meters (3281 feet) elevation.

The state's lowest elevation is 1010 meters (3315 feet) at the point on the eastern boundary of Yuma County where the Arikaree River flows into the State of Kansas. East of the Southern Rocky Mountains are the Colorado Eastern Plains of the High Plains, the section of the Great Plains within Colorado at elevations ranging from 3315 to 6562 feet (1010 to 2000 meters).

The states of Kansas and Nebraska border Colorado to the east. The plains are sparsely settled with most population along the South Platte and the Arkansas rivers. Rainfall is meager, averaging from 12 to 18 inches (300 to 450 millimeters) annually. There is some irrigated farming, but much of the land is used for dryland farming or ranching. Winter wheat is a typical crop and most small towns in the region boast both a water tower and a grain elevator.

The bulk of Colorado's population lives along the eastern edge of the Rocky Mountains in the Front Range Urban Corridor. This region is partially protected from prevailing storms by the high mountains to the west. To the west lies the eastern slope of the Rocky Mountains with notable peaks such as Longs Peak, Mount Evans, Pikes Peak, and the Spanish Peaks near Walsenburg in the south. This area drains to the east, is forested, and partially urbanized. With urbanization, utilization of the forest for timbering and grazing was retarded, which resulted in accumulation of fuel. During the drought of 2002 devastating forest fires swept this area.