1) On August 31, 1909, the electric streetcar service in Denver officially began, revolutionizing transportation in the city. The service expanded rapidly in the following years, with over 250 miles of electric tracks being laid by 1930.

2) In 1957, the Rocky Mountain National Park experienced one of its worst disasters when a flash flood swept through the park, killing 3 people and causing significant damage. The flood was caused by heavy rainfall that overwhelmed the park's drainage systems.

3) August 31, 1997 marked the opening ceremony of the inaugural Colorado State Fairgrounds in Pueblo, Colorado. The fairgrounds host a variety of events and activities throughout the year, including concerts, rodeos, and agricultural exhibitions.

4) The Colorado Labor Wars, a series of violent strikes and protests between miners and mine owners in Colorado, reached a turning point on August 31, 1903 when the US Army was called in to break up one of the strikes. The Army's involvement in the conflict ultimately led to the defeat of the striking workers and the consolidation of power among mine owners.

5) On August 31, 1955, the first iteration of the Colorado State Patrol Academy was established in Golden, Colorado. The academy trains state troopers who are responsible for enforcing traffic and criminal laws throughout Colorado.