In the spring General Sully returned with a brigade to prosecute another campaign against the Indians. His army now consisted of eleven companies of the Sixth Iowa Cavalry under Lieutenant-Colonel Pollock (Colonel Wilson having resigned); three companies of the Seventh Iowa Cavalry; a battalion of Minnesota Cavalry; two companies of Dakota Cavalry; a battery of four guns and howitzers and a company of scouts under Captain Nathaniel Pope. The whole command numbered about 1,800 men. On the 26th of June the army began a march of two hundred miles up the river, where a military post was erected and named Fort Rice. While here a brigade which had marched from Minnesota joined the expedition. On the 19th the army resumed its march northward, leaving a detachment of infantry to finish the fort. Following a divide between the Big Cannon Ball and Heart rivers the expedition moved on toward the Yellowstone. The passage through the “Bad Lands” was attended with great difficulties owing to the natural obstructions which sheltered and concealed the movements of the Indians. Dismounting his cavalry General Sully moved cautiously forward, driving the Indians from their lurking places, often meeting with determined resistance. The Yellowstone was reached on the 12th of August where two small steamers were waiting with supplies for the army.
With the assistance of the steamers the army with its trains was able to cross the river on the 13th and moved on toward Fort Union, a trading post on the Missouri River, on the border of the Crow Indian country. The expedition then proceeded westward to Fort Berthold, where one company of the Sixth Iowa Cavalry was left to garrison the post. The march was continued to “Dog Buttes” on the Mouse River, in search of hostile Indians but none were found and the army turned back reaching Fort Rice on the 9th of September. Here the active campaign for the summer ended. Bands of Indians were often seen in the vicinity for several weeks and while pursuing a party
