1. 1988: Denver International Airport Begins Construction
On November 21, 1988, construction began on what would become one of the largest airports in the world. Denver International Airport, or DIA, covers more than 33,000 acres and serves approximately 64 million passengers annually.

2. 1959: Colo. Governor Steve McNichols Breaks Ground on Cherry Creek Reservoir
On November 21, 1959, Colorado Governor Steve McNichols broke ground on the Cherry Creek Reservoir project, which included the construction of a dam and reservoir on Cherry Creek, southeast of Denver. The reservoir is a popular recreational area, offering boating, fishing, and camping opportunities.

3. 1922: The Denver Art Museum Opens
On November 21, 1922, the Denver Art Museum opened its doors for the first time, showcasing a growing collection of American Indian art and artifacts. Today, the museum's permanent collection contains more than 70,000 works of art.

4. 1905: The Colorado Labor Wars Come to an End
On November 21, 1905, the Colorado Labor Wars officially came to an end with the signing of the Charter of Peace, an agreement between striking coal miners and the Colorado Fuel and Iron Company. The conflict had started in September of 1913 and resulted in a violent struggle between miners, company employees, and law enforcement.

5. 1864: Sand Creek Massacre Takes Place
On November 21, 1864, Colorado Territorial Governor John Evans authorized a military attack on a peaceful village of Cheyenne and Arapaho Indians along Sand Creek in southeast Colorado. The massacre resulted in the deaths of more than 150 men, women, and children, and remains one of the darkest events in Colorado's history.