September 12

1878 On September 12, 1878, the Hayden Party, which spent the season exploring the thermal features of Yellowstone, left their camp at Mammoth for Yellowstone Lake. They viewed Mount Everts much of the day. Mount Everts was named by the Washburn party in 1870 for Everts, a member who was lost and found after 30 days of harrowing experiences.

1887 The Archer Post Office was established. In the early 1900s, as a result of the dry farming occurring in the region, an experimental station was established at Archer.

1919 The post office at Bill was established in Converse County; the grand opening of the Hot Springs County Carnegie Library was held.

1995 The Chief Joseph Scenic Highway was dedicated on September 12, 1995.