<Li> July 15--26: Camp Disappointment . Marias River does not go far enough north . Natives finally discovered . </Li> <Li> July 20: Sgt . Ordway's party (from Clark's party) meets Sgt . Gass's party at the Great Falls of the Missouri . </Li> <Li> July 27: Piikani Nation tribe members ("Blackfeet") try to steal Lewis's group's rifles . A fight broke out and two natives Americans were killed in the only hostile and violent encounter with a tribe . </Li> <Li> July 28: Lewis meets Ordway and Gass . </Li>

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