1. September 1, 1878: The first issue of the Rocky Mountain News was published in Denver, Colorado. The newspaper would remain in circulation until its closure in 2009.

2. September 1, 1907: The Colorado National Monument was established by President William Howard Taft. Located near Grand Junction, the monument features stunning red rock formations and hiking trails.

3. September 1, 1914: The first commercial flight in Colorado took place between Denver and Pueblo. The flight, operated by the Benoist Aircraft Company, took just over an hour and cost $25 per ticket.

4. September 1, 1942: Colorado inaugurated its first governor's mansion with the arrival of Governor John Vivian and his family. The mansion, located in Denver's Capitol Hill neighborhood, would serve as the governor's residence until 1959.

5. September 1, 2013: The devastating floods of 2013 began in Colorado, causing extensive damage and claiming the lives of ten people. The floods, which also impacted other states, were caused by heavy rainfall and caused over $3 billion in damage.