IMPORTANT FROM UTAH.
The St. Louis papers of the 11th instant furnish the following particulars of the latest news from Utah, briefly mentioned two or three days ago in our Telegraphic column. A portion of it is im-portant as confirming previous reports of the hostile disposition of the Mormons towards the United States forces which have been dispatched to their Territory:
FROM THE ST. LOUIS DEMOCRAT. A friend has permitted us to publish the follow-ing extract from a private letter, dated Fort Lara-mie, October 22, 1857:
"An express from the army on Haws' fork reports that the Mormons have destroyed three Government trains, (burnt them up.) BRIGHAM informed Col. ALEX-ANDER, by express, that he must not advance further into the Territory. Col. JOHNSTON is collecting the trains all together at the South Pass to escort them in. The 2d dragoons will be here to-morrow."
FROM THE ST. LOUIS REPUBLICAN.
Highly important intelligence has just been re-ceived at Fort Leavenworth, by express from Fort Laramie, with advices of October 22d. Lieut. Col. COOKE'S command of 2d dragoons were four miles this side, and had encountered a snow. storm five days previously. Col. ALBERT S. JOHNSTON was last heard from two hundred and thirty miles beyond Fort Laramie, and snow was seven inches deep one hundred miles this side of where the express left him. Owing to the slim supply of corn and entire ab-sence of grass, the teams of the entire command and the horses of the 2d dragoons were failing rapidly.
News had reached Laramie that the Mormons had burnt three Government trains (seventy-five wagons) near Green river, ninety miles behind Col. ALEXANDER'S command, (10th infantry,) which constituted the van-guard of the army. It was rumored that the 10th and 5th infantry and the batteries of artillery would go over and take possession of a Mormon village on Bear river for winter quarters. It is said that the dragoons had a month's supply of corn, at half allowance, and not a particle of grass. With snow on the ground at that, it seems like madness for them to proceed beyond Lara-mie; certainly such a step could only be justified in view of the prospect of actual hostilities this winter, of which no one at this distance can judge.
There was probably never before any portion of our army subjected to such privations, and to whom the fu-ture presents such a gloomy picture, as is the case at present with the "army for Utah." And it can be said, without disparagement to others, that no portion, of our army could have been better selected to battle with the hardships of a campaign which more than all others proves the soldier than the "army for Utah." The commander, Col. Albert S. Johnston, of the 2d Cavalry, stands among the first in ability in the army, with the indefatigatible Major Fitzjohn Porter at his elbow. Un-der his command, and emulating him in the patriotic zeal of warriors, are the respective commanders of the 10th Infantry, Colonel Alexander; and the 5th In-fantry, Lieut. Colonel Waite; while the trying duty, the almost hopeless task of conducting the "rear guard" (the six companies of 2d Dragoons) through a snowy path to its distant goal rests with Lieut. Col. Cooke. No one familiar with the operations of our army for the last twenty years will fear that any of these officers will prove recreant to the important trusts confided to them. We may rest assured that if, upon Col. Johnston's arrival on the verge of the Salt Lake Valley, circumstances urge the propriety of immediate action, offensively, towards the Mormons, it will be done with a bold and decisive hand. Certainly no act is better calculated to hasten the inevitable doom of Mormonism than this attempt on their part to destroy the army supplies. Nothing should shield them from the just retribution of an outraged Government. We doubt if Col. Johnston will be able, when his whole force is concentrated, to muster over one thousand men for duty. Such an army, so far from the base line, is too small to cope long with vigorous resist-ance.
The threatening aspect of affairs on our Western bor-der at this moment calls loudly for an increase of the army. Our wise Secretary of War and the President, it is earnestly hoped, will urge Congress to raise new re-giments early in the approaching session. The strength of our army is by no means commensurate with the ex-tensive Hue of defence, particularly the western portion. Should danger menace in Utah or Kansas, the troops in Florida, actively engaged in Indian warfare, must be transported rapidly to meet the new exigency, at an enormous expense, the change of climate and exposure operating disastrously to its efficiency; whereas, should our army be adequately increased (and the condition of our Western defences argues strongly for several addi-tional mounted regiments) by Congress this winter in time for organization for the field in the spring, the amount annually saved in the transportation of troops from point to point, which would then be unnecessary, would go far towards supporting the increase. But the great desideratum thereby gained would be security to emigration and protection to the hardy frontier settlers. Our army if full would not exceed fifteen thousand. Surely such a country as ours can afford 20,000.
