1. In 1904, the first automobile race in Colorado was held in Denver on October 4th. The race was only 20 miles long, but it sparked the interest of Coloradans in automobiles and racing.

2. In 1951, the University of Colorado Boulder became the first university in the United States to be awarded a federal contract to conduct research in space. This was the beginning of the university's involvement in America's space program.

3. In 1961, the Denver Broncos played their first game as a professional football team on October 4th against the Boston Patriots. Though the Broncos lost the game, the team's debut marked the beginning of professional football in Colorado.

4. In 1974, the first United States Grand Prix West race was held in Watkins, Colorado on October 4th. The race was won by Swiss driver Clay Regazzoni, who drove for the Ferrari team.

5. In 2009, the Colorado Rapids won their first ever trophy, the MLS Cup, on October 4th. The Rapids defeated the FC Dallas team in a thrilling game that went into extra time, with the final score being 2-1 in favor of the Rapids. This historic moment marked a major milestone for soccer in Colorado.