1. In 1906, the Great Falls Tribune reported a rare snowstorm in April that dumped up to 16 inches of snow on parts of Montana. This storm disrupted transportation and caused power outages in some areas.

2. On April 18, 1942, a B-17 bomber crashed near Bozeman, Montana, killing all 10 crew members on board. The crew was en route to Great Falls to train Royal Canadian Air Force pilots.

3. Montanan Art Jacobson, a former NFL player for the Green Bay Packers and Chicago Cardinals, was born on April 18, 1935. Jacobson played in two Pro Bowls and was inducted into the Montana Sports Hall of Fame in 2020, 10 years after his death.

4. In 1973, the Montana Legislature declared the fiddle the official state instrument, recognizing the importance of this instrument in the state's cultural heritage. This law was enacted on April 18 of that year.

5. On April 18, 1898, the Montana State Board of Health ordered all schoolchildren in the state to be vaccinated against smallpox. This measure was taken to stem an outbreak of the disease that had infected more than 100 people in the state.