Battle of the Tongue River
1865 CE.
Shown on the map at 44.906°, -107.163°.
The Battle of the Tongue River, sometimes referred to as the Connor Battle, was an engagement of the Powder River Expedition that occurred on August 29, 1865. In the battle, U.S. soldiers and Indian scouts attacked and destroyed an Arapaho village.
Text from the Wikipedia article Battle of the Tongue River, licensed CC BY-SA 4.0.