Colorado ( /k?l?'rædo?/ (help·info) or /k?l?'r??do?/ (help·info)) is a U.S. state located in the Rocky Mountain region of the United States of America. It may also be considered to be part of the Western and Southwestern regions of the United States. In rare cases Eastern Colorado is considered part of the Midwestern United States. Colorado entered statehood in 1876 and was nicknamed the “Centennial State”. It is bordered to the north by Wyoming, to the south by New Mexico and Oklahoma, at the southwest corner by Arizona, to the east by Nebraska and Kansas and to the west by Utah.

The state is well known for its magnificent scenery of mountains, rivers, lakes, and plains. The United States Census Bureau estimates that the state population was 5,024,748 on July 1, 2009, a 16.82% increase since the U.S. Census 2000. Denver is the capital of Colorado and the state's most populous city. Residents of Colorado are properly known as "Coloradans" although the archaic term "Coloradoan" is still used.