The Utah Expedition.
The following interesting letter from Col. Johnston was received at the War Department.
HEADQUARTERS ARMY OF UTAH,
South Pass en route to Salt Lake City,
October 18, 1857.
MAJOR : Accompanying this communication I send you two letters from Col. Alexander, the commander at present of the main body of the army of Utah. In his letter of the 8th of Oc- tober, Col. Alexander questions, by the hesita-tion with which he assumes them, his right to exercise fully all the duties of commander. His authority to exercise them without restriction is clearly granted by the 62d article of the ar-my, which specially directs who shall command in the absence of General Harney, or to be in- ferred, any other named commander, and suffi-ciently explains the objects of the expedition, and no question for the decision of the com- mander beyond his ordinary military duties could arise before the arrival of Governor Cum-ming.
Misapprehending the authority with which he is invested by law, and the orders of the general-in-chief, that portion of his letter respecting command would be, if he was correct in his view of his own position, a merited reflection upon his superiors, and it is therefore that I have ad-verted to it. Pursuing his design indicated in his letter of October 8, he, you will learn from his letter of October 14th, (herewith,) has ad-vanced up to Ham's fork of Green river, 35 miles above the crossing, (see map herewith,) and there directs the movements to be made by his own immediate command and the troops in his rear to form a junction, which, from errone-ous suppositions, would be wholly impractica- ble. First, he evidently believes thai Colonel Smith, escorting the remains of the supply trains, (in all about nine, including three set- lers' trains,) is advancing on the Kinney road or Cut-off with the force named in General Har-ney's order of August 18, and, of course, he has not received the countermand of that order. He assumes that the command in rear is capa-ble of a more rapid movement than his own; and, therefore, after waiting one day at the point in-dicated, will resume his march. In this, also, he would have been disappointed, as the trains in rear, suffering from fatigue and soarcity of subsistence, and without rest, which the teams with him have had, could not, if where he sup-posed them, overtake him
These are the facts, and, if known by Colonel Alexander, his disposition, as determined is his letter of October 8, would have been wholly dif-ferent. Colonel Smith is here at this camp, with fifty men of his regiment. I overtook him the day before yesterday (the 16th instant) about twenty miles east of this, and have added my escort, fifteen dismounted dragoons, to his force. Lieutenant Smith, in command of a squadron of dragoons and fifty of the tenth infantry, a force of about two hundred men, may be ex-pected here in three or four days. He is aware of the necessity of promptness, and I am sure will lose no time.
Mr. William Magraw, superintendent of the South Pass road, with a patriotism highly cred-itable to him, places at the disposition of the government as many of his employees as will volunteer. He thinks fifty or sixty will organ-ize, and I have agreed to accept their services, and have them mustered in for three or six months, as they may select; and he has also tendered fifteen good teams of mules and wag- ons, which I have also accepted, and directed them to be receipted for when delivered. Four supply trains, containing clothing, (of which the troops now in the advance, I am informed, begin to need,) ordnance, medical, and subsis- tence stores, are still in the rear, and may be expected in two or three days. The storm of last night may have destroyed some of their oxen, and on that account there may be more delay than I estimate. Eleven mules of Colonel Smith's train perished from cold last night.—The thermometer this morning at sunrise was at sixteen degrees below zero ; the sky is now clear and the thermometer at 1 o'clock stands at 34 ; and the small quantity of snow that fell during the night is melting, so that the animals can graze freely. I am thus minute that the reason for the order transmitted to Colonel Al- exander yesterday morning (herewith) may be fully comprehended. His intended movement, it met with opposition, would have so retarded his march as to have made it impracticable, and would have so probably entangled him in the midst of the deep snow of the valley of Bear river, which I understand never fails to fall there, and usually early in the season, as to place him beyond the means of extrication.—Our most potent enemy at the present is the snow, and constitutes at present our chief em- barrassment.
The movement of Col. Alexander (for the rea-sons I have mentioned, and of which he could not be apprized) would have separated him from supplies indispensable to the comfort and safety of the army, and deprived him of the assistance of the force which will be concentrated here in a few days, which, however small, being partly of cavalry, is of vital importance.
In ordering Col. Alexander to the mouth of Fontelle creek, a position about thirty miles from his camp on Ham's fork, I did so with the design of making a junction practicable. It is about seventy miles hence, and he can reach it by a good road, and without auy danger of sur- prise. There is there abundance of grass, and it is a point from which I can reach the region I intended to occupy this winter, without risk- ing the loss of our animals. As soon as the snow falls sufficiently on Green river to prevent the burning of the grass, I will march to Hen-ry's fork and occupy that valley during the win- ter. It is a commanding position, and accessi- ble two months earlier for reinforcements and supplies, by Cheyenne Pass, than any other, and will enable me to reach by Fort Bridger, and on the most direct route, to Salt Lake city as soon as practicable in the spring. At this position, also, Colonel Cook can join, which I still entertain the hope he will be able to do.
I greatly regret that the impossibility of con-centrating the troops destined for this service, and their supplies, will prevent a forward move-ment before spring. It is now manifest that before the force can be united the autumn will be too far advanced to move with a probability of sucess, though not opposed by the Mormons.
You are already apprized by the proclamation of Brigham Young, and his letter to Col. Alex-ander, which I transmitted on the 15th inst., of the political attitude assumed by the Mormons, and the resistance they meditate to the just authority the government desires to exercise in that Territory, and the general-in-chief no doubt has already considered the necessity of a con-quest of those traitorous people, and has esti- mated the force necessary to accomplish the ob- ject. With a fullview of the whole subject be-fore him, his great experience would not be benefitted by any suggestions of mine. I will, however, mention that unless a large force is sent here—from the nature of the country—a protracted war on their part is inevitable. The great distance from our source of supply makes it impracticable to operate with a small force. It in fact requires the employment of such force to guard numerous trains of the supplies, leav- ing but a small portion, if any, for offensive op-erations. A movement of troops from Califor-nia, Oregon, and by this route would terminate a war with the Mormons speedily, and more economically than if attempted by insufficient means.
In five or six days I think we will have all the force available here for such a forward move- ment. By that time the trains will all be up ; they should be here sooner. In twelve days from this time I expect to join Colonel Alexan-der at or near Fontelle creek.
The General may he assured that no retro- grade movement will be made by this force.
With great respect, your obedient servant,
A. S. JOHNSTON,
Colonel 2d Cavalry,
Com'ng the Army of Utah.
To Major Irvin McDowell, Assistant Adjutant General, Headquarters of the Army, New York city.