1. In 1875, the Colorado state legislature created the University of Colorado, which opened its doors in September of that year. The university was originally located in Boulder, but has since expanded to other locations throughout Colorado.

2. On April 3, 1916, the National Park Service was created in Colorado. The purpose of the agency was to manage and protect the country's national parks and other natural resources.

3. In 1968, the world’s largest diamond was discovered in Colorado on this day. The diamond, known as the Amarillo Starlight, weighed in at over 16 carats and was valued at over $80,000.

4. On April 3, 1984, Denver became the first American city to host the Winter Olympics. The games were held at various locations throughout the city, including the Pepsi Center and the University of Denver.

5. In 2020, Colorado experienced its largest single-day jump in COVID-19 cases on April 3, with 475 new cases reported. This marked a significant spike in the number of cases in the state, which had previously been relatively low compared to other parts of the country.