This event should not be confused with the Powder River Expedition (1865). The Big Horn Expedition, or Bighorn Expedition, was a military operation of the United States Army against the Sioux, and Cheyenne Indians in Wyoming Territory and Montana Territory. Although soldiers destroyed one Cheyenne and Oglala Sioux village, the expedition solidified Lakota Sioux and northern Cheyenne resistance against the United States attempt to force them to sell the Black Hills and live on a reservation, beginning the Great Sioux War of 1876. Background The Treaty of Fort Laramie (1868) granted the Lakota Sioux and their northern Cheyenne allies a reservation, including the Black Hills, in Dakota Territory and a large area of "unceded territory" in what became Montana and Wyoming. Both areas were for the exclusive use of the Indians, and whites except for government officials, were forbidden to trespass. In August, 1874, soldiers of the Black Hills Expedition under Lieutenant Colonel George A. Custer confirmed the discovery of gold in the Black Hills. This caused the United States to attempt to buy the Hills from the Sioux. The U.S. ordered all bands of Lakota and Cheyenne to come to the Indian agencies on the reservation by January 31, 1876 to negotiate the sale. Some of the bands did not comply and when the deadline of January 31 passed, the Commissioner of Indian Affairs, John Q. Smith, wrote that "without the receipt of any news of Sitting Bull's submission, I see no reason why...military operations against him should not commence at once." On February 8, 1876, General Phillip Sheridan telegraphed Generals George R. Crook and Alfred H. Terry, ordering them to undertake winter campaigns against the "hostiles". March 1-3 In bitterly cold weather, Brigadier General George Crook, commander of the Department of the Platte, marched north from Fort Fetterman near Douglas, Wyoming on March 1, 1876. General Crook's objective was to strike against the Indians while they were at their most vulnerable in their winter camps. Sitting Bull, Crazy Horse, and their followers were thought to be on the Powder, Tongue, or Rosebud rivers. Crook's force consisted of 883 men, including ten companies of United States cavalry, and two companies of infantry, along with civilian packers, scouts, guides, and a newspaper reporter, Robert Edmund Strahorn of Denver's Rocky Mountain News. Crook's highly valued chief scout was Frank Grouard, who had lived among the Lakota and spoke their language. Cattle