Precautions in dangerous defiles—­Trappers’ mode of defence on a prairie—­A mysterious visitor—­Arrival in Green River Valley—­Adventures of the detachments—­The forlorn partisan —­His tale of disasters.

As the route of Captain Bonneville lay through what was considered the most perilous part of this region of dangers, he took all his measures with military skill, and observed the strictest circumspection.  When on the march, a small scouting party was thrown in the advance to reconnoitre the country through which they were to pass.  The encampments were selected with great care, and a watch was kept up night and day.  The horses were brought in and picketed at night, and at daybreak a party was sent out to scour the neighborhood for half a mile round, beating up every grove and thicket that could give shelter to a lurking foe.  When all was reported safe, the horses were cast loose and turned out to graze.  Were such precautions generally observed by traders and hunters, we should not so often hear of parties being surprised by the Indians.

Having stated the military arrangements of the captain, we may here mention a mode of defence on the open prairie, which we have heard from a veteran in the Indian trade.  When a party of trappers is on a journey with a convoy of goods or peltries, every man has three pack-horses under his care; each horse laden with three packs.  Every man is provided with a picket with an iron head, a mallet, and hobbles, or leathern fetters for the horses.  The trappers proceed across the prairie in a long line; or sometimes three parallel lines, sufficiently distant from each other to prevent the packs from interfering.  At an alarm, when there is no covert at hand, the line wheels so as to bring the front to the rear and form a circle.  All then dismount, drive their pickets into the ground in the centre, fasten the horses to them, and hobble their forelegs, so that, in case of alarm, they cannot break away.  Then they unload them, and dispose of their packs as breastworks on the periphery of the circle; each man having nine packs behind which to shelter himself.  In this promptly-formed fortress, they await the assault of the enemy, and are enabled to set large bands of Indians at defiance.

The first night of his march, Captain Bonneville encamped upon Henry’s Fork; an upper branch of Snake River, called after the first American trader that erected a fort beyond the mountains.  About an hour after all hands had come to a halt the clatter of hoofs was heard, and a solitary female, of the Nez Perce tribe, came galloping up.  She was mounted on a mustang or half wild horse, which she managed by a long rope hitched round the under jaw by way of bridle.  Dismounting, she walked silently into the midst of the camp, and there seated herself on the ground, still holding her horse by the long halter.