1. The First Snow
In 2011, Colorado saw an unusual amount of snowfall in the Front Range region on October 31, marking the earliest first snow the area had seen in 15 years.

2. Haunted Hotel
The historic Stanley Hotel, located in Estes Park, Colorado, was the inspiration for Stephen King's horror novel, "The Shining." On October 31, 1974, King and his wife stayed at the hotel, and it was during their visit that King dreamed up the idea for his iconic novel.

3. The Birth of the State
Colorado became a state on August 1, 1876, but the official state holiday is celebrated on the last Monday of October, close to the date of October 31. This is because the first public school in the state was founded in 1861 on October 31.

4. The Most Expensive Floods
In 1997, Colorado experienced severe flooding throughout the state, resulting in around $3.3 billion in damages. October 31 was the day that the floods hit the northern region of the state, leading to the most expensive natural disaster in Colorado's history.

5. A Puzzling Halloween
In Denver, Colorado, the annual Halloween parade took a unique twist in 2015 when a massive cryptic crossword puzzle was created on the side of a building. The puzzle was over 100 feet tall and was created by two artists, who spent eight hours each day for four days creating the masterpiece.