1. On April 21, 1868, the first white settler in the Gallatin Valley, Oliver Boardman, arrived in Bozeman, Montana. He was a wagon master and farmer who established a large ranch in the area.

2. In 1933, the first airplane to land at the newly built Bozeman Municipal Airport arrived on April 21. The airport had been constructed by the Civilian Conservation Corps as a New Deal program during the Great Depression.

3. On April 21, 1945, the University of Montana's School of Journalism was established. It was the first journalism school in the state and has produced many successful journalists and media professionals over the years.

4. In 1964, a conference was held in Missoula on April 21 to discuss and raise awareness about the issue of pesticide pollution. The conference led to the establishment of the Environmental Defense Fund, a non-profit organization that advocates for environmental protection.

5. On April 21, 1979, the Montana Constitutional Convention opened in Helena. Over the next several months, delegates met to draft a new state constitution, which was then approved by voters in November of that year. The current Montana Constitution remains in effect today.