These great migratory herds of buffalo have their hereditary paths and highways, worn deep through the country, and making for the surest passes of the mountains, and the most practicable fords of the rivers.  When once a great column is in full career, it goes straight forward, regardless of all obstacles; those in front being impelled by the moving mass behind.  At such times they will break through a camp, trampling down everything in their course.

It was the lot of the voyagers, one night, to encamp at one of these buffalo landing places, and exactly on the trail.  They had not been long asleep, when they were awakened by a great bellowing, and tramping, and the rush, and splash, and snorting of animals in the river.  They had just time to ascertain that a buffalo army was entering the river on the opposite side, and making toward the landing place.  With all haste they moved their boat and shifted their camp, by which time the head of the column had reached the shore, and came pressing up the bank.

It was a singular spectacle, by the uncertain moonlight, to behold this countless throng making their way across the river, blowing, and bellowing, and splashing.  Sometimes they pass in such dense and continuous column as to form a temporary dam across the river, the waters of which rise and rush over their backs, or between their squadrons.  The roaring and rushing sound of one of these vast herds crossing a river, may sometimes in a still night be heard for miles.

The voyagers now had game in profusion.  They could kill as many buffaloes as they pleased, and, occasionally, were wanton in their havoc; especially among scattered herds, that came swimming near the boat.  On one occasion, an old buffalo bull approached so near that the half-breeds must fain try to noose him as they would a wild horse.  The noose was successfully thrown around his head, and secured him by the horns, and they now promised themselves ample sport.  The buffalo made prodigious turmoil in the water, bellowing, and blowing, and floundering; and they all floated down the stream together.  At length he found foothold on a sandbar, and taking to his heels, whirled the boat after him like a whale when harpooned; so that the hunters were obliged to cast off their rope, with which strange head-gear the venerable bull made off to the prairies.

On the 24th of August, the bull boat emerged, with its adventurous crew, into the broad bosom of the mighty Missouri.  Here, about six miles above the mouth of the Yellowstone, the voyagers landed at Fort Union, the distributing post of the American Fur Company in the western country.  It was a stockaded fortress, about two hundred and twenty feet square, pleasantly situated on a high bank.  Here they were hospitably entertained by Mr. M’Kenzie, the superintendent, and remained with him three days, enjoying the unusual luxuries of bread, butter, milk, and cheese, for the fort was well supplied with domestic cattle, though it had no garden.  The atmosphere of these elevated regions is said to be too dry for the culture of vegetables; yet the voyagers, in coming down the Yellowstone, had met with plums, grapes, cherries, and currants, and had observed ash and elm trees.  Where these grow the climate cannot be incompatible with gardening.