Just as he had given orders to this effect to his men, two signal guns were fired from the boats on the opposite side of the river.
At the same moment, a file of savage warriors was observed pouring down from the impending bank, and gathering on the shore at the lower end of the bar.

They were evidently a war party, being armed with bows and arrows, battle clubs and carbines, and round bucklers of buffalo hide, and their naked bodies were painted with black and white stripes.

The natural inference was, that they belonged to the two tribes of Sioux which had been expected by the great war party, and that they had been incited to hostility by the two chiefs who had been enraged by the refusal and the menace of Mr.Hunt.Here then was a fearful predicament.
Mr.Hunt and his crew seemed caught, as it were, in a trap.

The Indians, to a number of about a hundred, had already taken possession of a point near which the boat would have to pass: others kept pouring down the bank, and it was probable that some would remain posted on the top of the height.
The hazardous situation of Mr.Hunt was perceived by those in the other boats, and they hastened to his assistance.

They were at some distance above the sand-bar, however, and on the opposite side of the river, and saw, with intense anxiety, the number of savages continually augmenting, at the lower end of the channel, so that the boat would be exposed to a fearful attack before they could render it any assistance.