The state of Colorado uses the abbreviation "CO." The 31st state admitted to the Union, the Centennial State rests at the heart of the Rocky Mountains and boasts the highest mean elevation of any state.
Colorado is known for its 54 'fourteeners,' mountain peaks rising at least 14,000 feet above sea level. Along with Utah, Arizona and New Mexico, Colorado is part of the "four corners" geographical region where the four states come together. Much of the state's revenue is generated from tourism, as the state boasts breathtaking scenery and world-class skiing. The state occupies roughly 103,642 square miles. The capital and largest city of Denver lies in the state's north-central region.