1. Pearl Harbor Remembrance Day: December 7, 1941, is a significant day in Colorado history because it was the day that Japan attacked the United States at Pearl Harbor. This event led to the United States’ entry into World War II. Many Coloradans joined the military to fight in the war effort.

2. Ski Train Service: On December 7, 1940, the Ski Train Service began running from Denver to Winter Park. The train was a popular way for Denver residents to get to the mountains for skiing and other winter sports. The Ski Train Service operated for over 70 years before ending in 2009.

3. The Ludlow Massacre: On December 7, 1914, the Colorado National Guard attacked striking coal miners and their families in Ludlow, Colorado. The attack led to the deaths of several people, including women and children. The event became known as the Ludlow Massacre and is an important moment in the history of organized labor in the United States.

4. Colorado Statehood Day: December 7 is also Colorado Statehood Day, which celebrates the day that Colorado became the 38th state to join the Union. On December 7, 1876, President Ulysses S. Grant signed the proclamation admitting Colorado to the United States.

5. Broncos Win Super Bowl XXXIII: On December 7, 1998, the Denver Broncos defeated the Green Bay Packers to win Super Bowl XXXIII. The game was played in San Diego, California, and was the second Super Bowl win for the Broncos in as many years. Many Coloradans cheered on the Denver team as they brought home the championship.