1. The Sand Creek Massacre occurred on November 25, 1864, in southeastern Colorado. Led by Colonel John Chivington, a volunteer force attacked a peaceful village of Cheyenne and Arapaho Indians, killing between 150 and 200 men, women, and children.

2. The Denver and Rio Grande Railroad completed a narrow-gauge line between Alamosa and Durango on November 25, 1881. The route, which traversed the San Juan Mountains, became known as the "Scenic Line of the World" and remains a popular tourist attraction today.

3. November 25, 1929, marked the opening of Red Rocks Amphitheatre near Morrison. The natural outdoor venue, known for its acoustics and stunning views of the Denver skyline, has hosted countless concerts and events over the years.

4. The first-ever ski lift in the United States opened at Loveland Ski Area on November 25, 1936. The rope tow was designed by Robert and Joyce Patterson and revolutionized skiing by making the sport more accessible to the general public.

5. On November 25, 2013, Colorado became the first state to legalize the recreational use of marijuana. The decision marked a significant shift in drug policy and has since spurred a new industry in the state, with retail marijuana shops and marijuana-infused products becoming increasingly common.