1. Colorado became a state on October 1, 1876. This day is celebrated as Colorado Day, a state holiday.

2. The first permanent school in Colorado opened its doors on October 1, 1859. The school was located in a log cabin in present-day Denver.

3. In 1908, the state's oldest continuously operated movie theater, the Isis Theatre, opened its doors in Colorado Springs on October 1. It is still in operation today, over 100 years later.

4. On October 1, 1942, the world's first atomic energy plant, known as the "Atomic City," began operations in Colorado. This plant was used to produce plutonium for nuclear weapons during World War II.

5. The deadliest avalanche in U.S. history occurred on October 1, 1913, on the Continental Divide near Georgetown, Colorado. It claimed the lives of 96 people, most of whom were railway workers who were clearing the tracks in preparation for the winter season.