In August 7, 1877, the fleeing Nez Perce crossed the Bitterroot Mountains over Lolo Pass and entered the Big Hole valley in Western Montana.  They made camp along the Big Hole River and expected to rest their horses and heal their exhausted and wounded people.  After leaving Idaho Territory it was assumed by Chief Looking Glass that their troubles with Idaho and the army were far behind them. 

In the wee hours of August 9th the sleeping camp was attacked by the US Army under Colonel John Gibbon and civilian volunteers.  The Nez Perce, even though weary and with much fewer resources, gained the upper hand and on the second day they escaped Southward toward Yellowstone Park hoping for help from their longtime friends, the Crow.