The Battle of Bone Pile Creek, part of the Powder River Expedition, was fought August 13–15, 1865, by United States soldiers and civilians against Sioux and Cheyenne warriors.

The battle occurred near Bone Pile Creek, in Dakota Territory, in present-day Campbell County, Wyoming.

[1] On August 13, 1865, the soldiers, civilians, and wagon train of Lieutenant Colonel James A. Sawyers' Expedition were moving west.

Sawyers agreed to give the supplies, which included a wagon full of sugar, bacon, coffee, flour, and tobacco, though Captain Williford objected to the idea.

When the wagons began moving again, the Indians attacked, killing Privates Anthony Nelson, and John Rouse of Company B, 1st Dakota Cavalry.