1. On August 3, 1858, a group of pioneers led by William Greeneberry Russell discovered gold near the present-day city of Denver, sparking the Colorado Gold Rush. This discovery led to the establishment of mining towns throughout the state and fueled Colorado's economy for decades.

2. On August 3, 1876, Colorado was admitted as the 38th state in the United States. The state's entry into the union marked the culmination of a long struggle for statehood and established Colorado as an important political and economic power in the West.

3. On August 3, 1904, the first motorized fire engine in the United States was put into service in Denver. The fire engine, which was equipped with a gasoline engine and a 65-feet ladder, revolutionized firefighting and helped to make the city safer for its residents.

4. On August 3, 1975, the Colorado Rockies played their first game as a Major League Baseball team at Mile High Stadium in Denver. Although the team struggled in its early years, it eventually became a beloved institution in Colorado and helped to establish the state as a sports destination.

5. On August 3, 2013, the Colorado State Fair opened in Pueblo, Colorado. The fair, which has been held annually since 1869, features a wide range of agricultural exhibits, carnival rides, and concerts. It is attended by hundreds of thousands of people each year and is an important celebration of Colorado's rural heritage.