1. On June 21, 1870, the first passenger train arrived in Helena, Montana, bringing with it a new era of transportation and commerce to the area.

2. The famous Battle of the Little Bighorn, also known as Custer's Last Stand, took place on June 21, 1876, near present-day Crow Agency, Montana. The battle was a significant event in U.S. history, as it marked the final defeat of General George Custer and his cavalry against the Sioux and Cheyenne Indian tribes.

3. Glacier National Park officially opened to the public on June 21, 1910. The park, located in the Rocky Mountains, is known for its beautiful scenery, including glaciers, lakes, mountains, and forests.

4. On June 21, 1966, Billings, Montana, experienced a record-breaking tornado outbreak, with 11 tornadoes touching down in and around the city. The tornadoes caused significant damage, but no fatalities.

5. In 2021, June 21 marked the summer solstice, the longest day of the year in terms of daylight hours. Montana residents celebrated the solstice with events such as outdoor concerts, yoga classes, and hiking expeditions.