History of Montana degree of longitude northward to the boundary line of the British possessions. The boundaries of Montana territory did not change during its existence. Montana was admitted to the Union as the state of Montana on November 8, 1889. The Battle of the Little Bighorn—also called Custer's Last Stand and the Battle of the Greasy Grass—was an armed engagement between a Lakota (Sioux)-Northern Cheyenne-Arapaho combined force and the 7th Cavalry of the United States Army. It occurred June 25–June 26, 1876, near the Little Bighorn River in eastern Montana Territory near present-day Hardin, Montana, on land that today is part of
Little Bighorn River along the tributaries commonly use the shortened version—Little Horn—instead of the more cumbersome name, Little Bighorn. A historical variant name for the Little Bighorn is the Greasy Grass. From the 1500s to the 1800s, the indigenous Crow people knew the river as the Greasy Grass. Crow tribal historian Joe Medicine Crow explained in a 2012 YouTube interview that this name was used by the Crows for the river system because in the river bottoms in the upper reaches of the Little Bighorn and its major tributaries there was abundant grass that would gather heavy dew in the morning which, in