1. On June 15, 1876, the Battle of the Rosebud occurred in southeastern Montana, a precursor to the Battle of Little Bighorn. General Crook led 1,000 troops against a large group of Cheyenne and Sioux warriors. The Native Americans fought a successful defensive battle, which ultimately led to the defeat of General Custer at Little Bighorn just nine days later.

2. June 15, 1887, saw the founding of the small town of Bynum, Montana. The town was named after Alexander Bynum, a prominent merchant in the area. Today, Bynum has a population of just over 30 people.

3. In 1916, on June 15, the Montana State School of Mines was established in Butte, Montana. The school was created to provide mining engineers for the growing mining industry in Montana. Today, the Montana Tech campus is home to five Colleges that offer degrees in a variety of fields.

4. On June 15, 1938, Geraldine Lucas became the first woman to serve as a county commissioner in Montana. She represented Pondera County in north-central Montana and was re-elected three times, serving a total of twelve years in office.

5. Finally, in 1951, on June 15, the Montana State Capitol Building in Helena was officially dedicated. The building has a neoclassical design and was constructed using Montana sandstone. It features a large rotunda with a copper dome, which is a popular attraction for visitors to Helena.