1. Colorado became a state on December 6, 1876, making it the 38th state to join the United States of America. This day is celebrated as Colorado Day each year.

2. In 1917, Colorado enacted the first law that allowed women to vote in the state's elections. This move came three years before the 19th Amendment was ratified, giving women the right to vote nationally.

3. On December 6, 1907, a massive explosion ripped through the Monarch Mines in Colorado, killing 27 miners. The disaster was caused by a buildup of methane gas and led to a public outcry over the lack of safety regulations in the mines.

4. Colorado's Mesa Verde National Park was established on December 6, 1906. The park is home to over 5,000 archeological sites and protects some of the best-preserved cliff dwellings in the world.

5. In 2005, Colorado became the second state in the US to legalize the use of recreational marijuana. The law went into effect on December 6, 2012, making it legal for adults over 21 to possess and use marijuana in limited amounts.