Nomadic hunters roamed the area that is now Colorado thousands of years ago. About the first century A.D., a people known as the Anasazi, or Basketmakers, settled in what is now the southwestern part of the state. Their descendants, the Cliff Dwellers, flourished from about 1000 to 1300 A.D. Various Indian tribes were inhabiting the land when the first European explorers reached the Colorado region in the 16th century. The dominant tribes at that time were the Cheyenne and Arapaho, who lived on the eastern plains, and the Ute, who were mountain-dwellers.

Important dates in Colorado
1706 Juan de Ulibarri claimed the Colorado region for Spain.
1803 The United States acquired eastern Colorado as part of the Louisiana Purchase.
1806 Zebulon M. Pike explored Colorado.
1848 The United States took western Colorado after the Mexican War.
1858 Gold was discovered at Dry Creek, near the site of what is now Denver.
1859 The Colorado gold rush attracted thousands of prospectors and settlers.
1861 Congress created the Colorado Territory.
1870 The Denver Pacific Railroad was completed to Denver.
1876 Colorado became the 38th state on August 1.
1879 The Meeker Massacre marked the end of serious Indian fighting.
1899 The state's first beet-sugar factory began operating.
1906 The U.S. Mint in Denver issued its first coins. Congress established Mesa Verde National Park.
1915 Rocky Mountain National Park was established.
1927 The Moffat Tunnel, a railroad tunnel through the mountains, was completed.
1956 The Colorado River water storage project was approved by Congress.
1958 The U.S. Air Force Academy's permanent campus opened near Colorado Springs.
1959 The Colorado-Big Thompson irrigation system was completed.
1962 Ground was broken for the three-dam Curecanti water storage system (now the Wayne N. Aspinall Storage Unit). The system was completed in 1976.
1985 The Frying Pan-Arkansas Project, which transfers water across Colorado, was completed.
1999 Black Canyon of the Gunnison National Monument was made a national park.
2004 Great Sand Dunes National Monument became a national park.

Important dates in Colorado