1. In 1943, the U.S. Army opened the Fort Peck Dam, which is located on the Missouri River and is the largest hydraulically filled dam in the world. The project required the relocation of over 50 towns and communities, and employed over 10,000 workers at its peak.

2. On January 9, 1884, Montana's first public library, the Montana Territorial Library, was established in Helena. It was later designated as the state library when Montana became a state in 1889.

3. In 1918, the Montana State Legislature passed the Montana Sedition Act, which made it a crime to express opposition to the United States' involvement in World War I. The act led to the arrest and imprisonment of several Montanans for their anti-war views.

4. On January 9, 1826, fur trader Robert Campbell established Fort Raymond (later renamed as Fort Union) on the Missouri River. The fort served as an important hub for the fur trade in Montana and the surrounding region for many years.

5. In 2008, gold was discovered in the Rock Creek drainage area in southwestern Montana, leading to renewed interest in gold mining in the state. Gold mining has a rich history in Montana, with the first major discovery occurring in 1862 near the town of Bannack.