The Commissioner of Indian Affairs instructed his agents to warn the chiefs to call in all Indians away from the reservation, notifying that all found away would be punished. This only excited the war-like young bucks and caused them to move in the early spring as far west as they could go. At that time the buffalo were driven by encroaching settlements and the railroads from their southern grazing grounds into the country west and north of the Sioux reservation. Crook first met the Indians in a slight engagement on Tongue River, Montana. Terry, meanwhile, so separated from Crook by distance and hostile Indians as to prevent communication, had searched for the hostiles on the north. He discovered their trail on the Yellowstone at the mouth of the Rosebud, and organized an expedition under General Custer with the entire 7th Cavalry to pursue it. General Crook's expedition is described in detail (Appendix, 400), save what occurred after his separation from General Terry's command. The hostile Indians separated, some going to Canada and others turning eastward. General Crook determined to follow the latter, depending entirely on pack mules for transportation. With scanty rations, he undertook a long and distressing march through the dry and barren country, with little knowledge of its streams and trails. Both men and officers became restless and many of the horses were shot for want of sustenance. When near the Missouri River, Crook turned southwest toward the Black Hills, crossing the North and South Cannonball rivers. Here many officers and men became dismounted, and it was feared they might perish for want of rations. There was no game, many ate horse flesh, and had no knowledge of woodcraft, course, or direction. On the 8th of September, as I was bringing in the rear squadron of the command, having shot seventy horses that day, General Crook, in consultation with General Merritt, directed me to select one hundred and fifty of the best men and horses from my regiment, take Chief Packer Moore, with fifty pack mules, to Deadwood, in the Black Hills, and bring back supplies to the command. His last words were that should I encounter a village I should attack and hold it. It was nine o'clock before I could collect my command, and I left so hurriedly that no medical officer was sent with me. The night was very dark. I took with me Grouard, one of the best scouts we had, especially proficient in woodcraft. Although there were no stars and insufficient light to see the surrounding land, somehow Grouard took us in the right direction. About midnight he lighted a match and showed me the fresh tracks of ponies on the banks of a little lake. We were close to the Indians. It began to rain as we lay down, holding the lariats of our horses, and it was with difficulty that we obtained a little sleep. It was still raining at daylight, but we were early up and off, seeing by the mountain ranges we were going toward the Black Hills.