The Third Cavalry was divided into three battalions, one of four, and two of three troops each. Captain Mills commanded the first battalion, Captain Henry the second, Captain Van Vliet the third. Crook acted promptly. He sent forward three companies of his infantry, deploying them as skirmishers, to line the river bank and open fire on the Indians in plain view on the bluff on the other side. At the same time he ordered Captain Mills to take his battalion across the river and charge the enemy. The Sioux were already unsettled by the accurate fire of the infantry with their long-range rifles, and as Mills’ battalion deployed, dashed through the water and at the steep bluffs on the other side, they broke and fled, having suffered little or no loss, and not having inflicted much more. IV. The Flying Column The skirmish was simply a grim earnest of the determined purpose of the Indian chief. No pursuit was attempted at that time. Negotiations had been entered into between the Crows, who were the hereditary enemies of the Sioux, and the Shoshones, with a view to securing a body of Indian auxiliaries to the troops, whose services would be invaluable for scouting. Persuaded thereto by Frank Gruard,[60] a celebrated scout, something less than two hundred Crows, with eighty odd Shoshones, joined the army on the 15th of June. To pursue Indians while incumbered with infantry and a wagon train was well nigh a hopeless task. Crook determined to park the wagons and baggage, leave them under the command of Major Furey, the quartermaster, strip his command to the lightest marching order, and make a dash for the Rosebud River and the Indian country. One hundred infantrymen, protesting most vehemently against their orders, to their credit, be it said, were detailed to remain with the train. Two hundred others, who professed to have some skill in riding, were mounted on the mules of the wagon train to accompany the cavalry. The morning of the 15th was spent in accustoming the infantrymen to the mules and the mules to the infantrymen. The cavalrymen and the Indian allies enjoyed the circus which ensued when the mules were bridled and saddled for the first time, and mounted by men who had never before straddled anything more formidable than a fence rail. It took the whole morning before the infantrymen and the mules learned to get along with each other, even in a half-hearted way.