Mounted Rangers, with one or two mountain howitzers, will scour the whole region east of the Missouri, and drive all the fragments of Indian bands to the northwest of the line of posts. The Indians will be attacked and beaten, or notified, under the penalty of immediate and active hostilities, that they must not venture behind the line on any pretext. The whole region east of the Missouri and north of the line of posts will be traversed by this cavalry force as thoroughly as possible during the summer. In like manner, whilst the post near Fort Clarke, on the Missouri River, is being established by its infantry garrison, General Sully, with a regiment and battalion of cavalry, will make an expedition from For pierre, by way of the Black Hills and the upper Yellowstone, through the country of the Uncpapa Sioux, and will, if practicable, locate the post on the upper Yellowstone.

An examination of the maps will exhibit better than I could explain the important results of these expeditions and of the establishment of these posts, in forcing the whole of the Yanktonais Sisseton Sioux, who have endangered the frontiers of Iowa and Minnesota and obstructed the navigation of the Red River of the North, to the northwest of the line of posts through Dakota, and to such a distance as to insure entire security hereafter, in opening to emigration and settlement all of Dakota east and south of James River, and in furnishing a direct and much safer route for emigrants to Idaho. The wonderful accounts of gold found in that Territory have greatly inflamed the minds of the people throughout the Northwest, and a very heavy emigration will begin in the spring. Of course there will be much suffering and perhaps not infrequent massacres of the emigrants by Indians. Such people are proverbial careless and imprudent, but, notwithstanding, the Government will be held responsible for any repetition of the sufferings which marked the early overland travel to California.

To accomplish the purposes herein stated, the following forces (now in the department) will be used, viz: One regiment of infantry and the regiment of mounted rangers in Minnesota. This force will furnish garrisons for the posts at Devil's Lake and on James River, and the small garrisons at Forts Ridgely, Abercrombie, and Ripley. About eight companies of infantry, a regiment of cavalry (the Sixth Iowa), and another battalion of cavalry for a few months of the summer will be required by General Sully for the occupation of the post below Fort Clarke, and for his expedition by way of the Black Hills to the upper Yellowstone and Missouri Rivers. This force (except the last battalion of cavalry) is now in this department.

In all, the necessary troops will consist of two regiments infantry and two regiments and a battalion of mounted men. The battalion of mounted men is only needed for temporary service and can be borrowed for a few months from Nebraska, especially as its movements will be against the Sioux, who endanger the overland route thought that Territory. The establishment of these posts, together with active operations of the whole cavalry force during the summer, will, I doubt not, effectually put an end to Indian hostilities on the frontier of Iowa and Minnesota, and accomplish all the purposes set forth in this communication. The posts will be built by the troops from material on the ground, without any necessity for appropriations, and will no doubt soon become permanent settlements along the emigrant route. The stay of the troops will only be temporary, as the country behind and around the posts will soon be settled. The