1. On April 23, 1859, the first gold rush in Colorado officially began when gold was discovered in the area that would become known as Gregory Gulch.

2. On April 23, 1904, the first Denver Post building was constructed on the corner of 15th and California Street in Downtown Denver. The newspaper would go on to become one of the largest and most influential in the state.

3. On April 23, 1910, the first passenger train arrived in the town of Sterling, Colorado, officially bringing rail transportation to the area.

4. On April 23, 1934, a tornado touched down near the town of Anton in northeastern Colorado, causing extensive damage and injuring several people.

5. On April 23, 1988, the second deadliest aviation disaster in Colorado history occurred when a Continental Airlines flight crashed near Stapleton International Airport, killing 17 people. The crash was later attributed to pilot error.