Unfortunately, as an AI language model, I do not have the capability to browse through historical events to gather information about a specific day in Montana's history. However, I can offer some general facts about October 30:

1. October 30 is the 303rd day of the year in the Gregorian calendar, with 62 days remaining until the end of the year.
2. On this day in 1831, the city of London Bridge was completed and opened to the public.
3. The deadliest Atlantic hurricane in history, known as the "Great Hurricane," reached its maximum intensity on October 30, 1780. It caused over 22,000 deaths in the Caribbean and southeastern United States.
4. In 1974, Muhammad Ali became the heavyweight boxing champion for the second time by defeating George Foreman in the "Rumble in the Jungle" fight in Kinshasa, Zaire.
5. October 30 is celebrated as National Candy Corn Day in the United States, honoring the popular Halloween candy that is shaped like a kernel of corn.

These are just a few general facts about October 30. While I cannot provide specific information about this day in Montana's history, I hope these facts were interesting and informative.