The region that is today the U.S. State of Colorado has been inhabited by Native Americans and their Paleoamerican ancestors for at least 13,500 years and possibly more than 37,000 years. The eastern edge of the Rocky Mountains was a major migration route that was important to the spread of early peoples throughout the Americas. The Lindenmeier site in Larimer County contains artifacts dating from approximately 8720 BCE.

Colorado is a landlocked state in the Mountain West subregion of the Western United States. Colorado borders Wyoming to the north, Nebraska to the northeast, Kansas to the east, Oklahoma to the southeast, New Mexico to the south, Utah to the west, and meets Arizona to the southwest at the Four Corners. Colorado is noted for its landscape of mountains, forests, high plains, mesas, canyons, plateaus, rivers, and desert lands. Colorado is one of the Mountain States and is often considered to be part of the southwestern United States. The high plains of Colorado may be considered a part of the midwestern United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is the eighth most extensive and 21st most populous U.S. state. The United States Census Bureau estimated the population of Colorado at 5,877,610 as of July 1, 2023, a 1.80% increase since the 2020 United States census.