1. In 1876, General George Crook's troops engaged in a battle with Sioux and Cheyenne warriors near the Rosebud River. This was a significant event in the Plains Indian Wars, which took place in Montana and other western states during the late 19th century.

2. On June 20, 1901, the Montana School of Mines (now Montana Tech) was established in Butte. This institution has a long history of providing education and training in mining, engineering, and other technical fields.

3. In 1928, the famous Butte-Anaconda road race was held on June 20. This event was a highlight of the Montana racing circuit, and attracted top drivers and teams from across the region.

4. In 1944, a devastating forest fire swept through the Flathead National Forest, destroying several small towns and killing 15 people. This fire is still remembered as one of the worst natural disasters in Montana history, and was a major turning point in forest management practices.

5. On June 20, 1963, President John F. Kennedy spoke in Great Falls as part of his tour of Western states. The President's remarks focused on issues such as conservation, resource management, and development of the region's economy. Kennedy's visit helped to highlight Montana's importance as a key player in the national debate over these issues.