Powder River Expedition (1865)

The Powder River Expedition, also known as the Powder River War, was a large-scale military operation conducted by the United States Army in 1865 against the Lakota Sioux, Cheyenne, and Arapaho tribes in the Powder River Country of present-day Wyoming and Montana. The primary goals of the expedition were to punish the tribes for attacks on white settlers and travelers along the Bozeman Trail, and to establish a permanent military presence in the region to protect the trail.

The expedition was commanded by Brigadier General Patrick E. Connor and consisted of three main columns. Connor led the central column, which was the largest. Other columns were led by Colonel Nelson Cole and Colonel Samuel Walker. The expedition suffered from poor planning, logistical problems, and a lack of coordination between the columns.

Several significant engagements took place during the Powder River Expedition, including the Battle of the Tongue River (also known as the Connor Battlefield) on August 29, 1865, where Connor's forces attacked an Arapaho village. While counted as a victory, the village was mostly abandoned, and the supplies taken were limited. Cole and Walker's columns suffered from severe shortages of supplies and were forced to retreat after skirmishes with the Native American tribes. The columns failed to effectively coordinate with each other, leading to a significant weakening of the overall mission.

The Powder River Expedition is generally considered a failure. While it did result in some Native American casualties and the destruction of some property, it failed to achieve its primary objectives of pacifying the tribes and securing the Bozeman Trail. The expedition also exacerbated tensions between the U.S. government and the Plains Indians, contributing to further conflicts in the years that followed, ultimately leading to Red Cloud's War. The high cost of the expedition, coupled with its limited success, led to criticism of Connor and the overall conduct of the campaign.