Cantonment Reno also known as Fort McKinney 1 was a US Army post or cantonment located on the Powder River near the old Bozeman Trail crossing. A previous fort near the site had been abandoned and burned after the Fort Laramie Treaty of 1868. Cantonment Reno was re-established in late 1876, just upstream of the site of old Fort Reno. Cantonment Reno started as a temporary base of operations for General George Crooks' 1876 Big Horn Expedition,. Crook's Expedition was part of the intensive campaign against the Sioux and Cheyenne in late 1876, following Custer's defeat at the Battle of the Little Bighorn.

The Dull Knife Fight, or the Battle on the Red Fork, part of the Great Sioux War of 1876, was fought on November 25, 1876, in present-day Johnson County, Wyoming between soldiers and scouts of the United States Army and warriors of the Northern Cheyenne. The battle essentially ended the Northern Cheyennes' ability to continue the fight for their freedom on the Great Plains.