McKenzie also rebuilt the Bighorn post, this time as Fort Cass, and thus controlled all the fur trade of the upper Missouri and the Yellowstone. He advised the company to get a river steamboat to bring the supplies up and the furs down the river. The company then ordered the steamboat Yellowstone built on contract. The boat made its first run to Fort Union in 1832, with the western artist George Catlin as one of its passengers. Catlin recorded the life at the post, in sketches and in his journal. In this extract he describes a buffalo hunt:
I mentioned the other day that M'Kenzie's table from day to day groans under the weight of buffalo tongues and beavers' tails, and other luxuries of this western land. He has within his fort a spacious ice-house, in which he preserves his meat fresh for any length of time required; and sometimes, when his larder runs low, he starts out, rallying five or six of his best hunters (not to hunt but to "go out for meat"). He leads the party mounted on his best buffalo horse (i.e. the horse amongst his whole group which is best trained to run the buffalo) trailing a light and short gun in his hand, such a one as he can easily reload whilst his horse is at full speed….
They had five or six men, each with a cart, follow to bring in the meat. Then they rode out west of the post and climbed out of the river bottom to the open plain.
There in full view of us was a fine herd of some four or five hundred buffaloes, perfectly at rest…. Some were grazing, and others were lying down sleeping; we advanced within a mile or so of them in full view. Mons. Chardon "tossed the feather" (a custom always observed to try the course of the wind), and we commenced "stripping" as it is termed (i.e. every man strips himself and his horse of everything extraneous and unnecessary appendages of dress, etc., that might be an encumbrance in running). Hats are laid off, and coatsand bullet pouches; sleeves are rolled up, a handkerchief is tied lightly around the head, and another around the waistcartridges are prepared and placed in the waistcoat pocket, or half a dozen bullets "throwed into the mouth,'' all of which takes some ten or fifteen minutes, and is not, in appearance and effect, unlike a council of war. Our leader lays the whole plan of the chase, and preliminaries all fixed, guns charged and ramrods in our hands, we mount and start for the onset. The horses are all trained for this business and seem to enter into it with as much enthusiasm, and with as restless a spirit as the riders themselves. While stripping and mounting, they exhibit the most restless impatience, and when "approaching" (which is all of us abreast, upon a slow walk and in a straight line toward the herd until they discover us and run) they all seem to have caught the spirit of the chase, for the laziest nag amongst them prances with an elasticity in his step, champing his bithis ears erect, his eyes strained out of his head, and fixed on the game before him, whilst he trembles under the saddle of his rider. In this way we carefully and silently marched until within forty or fifty yards, when the herd discovering us, wheeled and laid their course in a mass. At this instant we started (and all must start for no one could check his steed at that moment of excitement) and away all sailed, and over the prairie flew, in a cloud of dust, which was raised by their trampling hoofs. M'Kenzie was foremost in the throng; and soon dashed amidst the dust and was out of sighthe was after the fastest and fattest. I had discovered a huge bull whose shoulders towered above the whole band, and I picked my way through the crowd to get alongside of him. I went not for "meat," but for a trophy. I wanted his head and horns. I dashed along through the thundering mass as they swept over the plain, scarcely able to tell whether I was on a buffalo's back or my horsehit, and hooked, and jostled about, till at length I found myself alongside of my game, when I gave him a shot as I passed him. I saw guns flash in several directions about me, but I heard them not. Amidst the trampling throng Mons. Chardon had wounded a stately bull, and at this moment was passing him again with his piece leveled for another shot; they both at full speed, and also within reach of the muzzle of my gun, when the bull instantly turned and receiving the horse upon his horns, and the ground received poor Chardon, who made a frog's leap of some twenty feet or more over the bull's back and almost under my horse's heels. I wheeled as soon as possible and rode back where lay poor Chardon, gasping to start his breath again and within a few paces of him his huge victim, with his heels high in the air and the horse lying across him…. In a few moments he arose, picked up his gun, took his horse by the bit; which then opened its eyes… sprang to his feet, shook off the dirt, and here we were, all upon our legs again, save the bull….
I rode back with M'Kenzie, who pointed out five cows which he had killed, all of them selected as the fattest and slickest of the herd. This astonishing feat was all performed at full speed, within the distance of one mile, and every one shot through the heart….
In the short space of time required for a horse under full whip to run the distance of one mile he had discharged his gun five times, and loaded it four timesselected his animals, and killed at every shot. [Note: McKenzie was using a muzzle loader, charged with powder and ball, and a percussion cap.]
Such is the mode by which white men live in this countryand such is one of their delightful amusementsat the hazard of every bone in one's body, to feel the fine and often thrilling exhilaration of the chase for a moment, and then as often upbraid and blame himself for his folly and imprudence.
On another chase Catlin was thrown from his horse and had the stock of his gun broken in the fall. His horse ran away too, and had to be chased on foot for a distance, but Catlin escaped with only a few bruises. The successful hunt described here secured enough meat to fill five carts and load several pack horses, possibly two tons in all. The bulls and the trimmings from the cows were left for the wolves.
Kenneth McKenzie, with a gift for securing able, well-trained men, was able by exercising considerable tact, patience, and firmness to keep the Blackfeet reasonably peaceful for the next decade or so, to the benefit of the American Fur Company's trade. He even managed a short truce between the Blackfeet and the Assiniboins, the latter promising to stay east of the mouth of the Milk River and to do their trading at Fort Union. This truce lasted a year and ended abruptly when the Assiniboins made a dawn attack against a Blackfoot camp under the walls of the upriver post.
Although the Blackfeet suspended hostilities around the trading post, they were fighting with nearly everybody in sight, especially those to the south and west. When they went to war during this period, particularly against the Shoshoni, they wanted to gain more than just the honors from coups: they wanted to exterminate the enemy and take over his landa war of conquest. This pattern comes out strongly in a study of their conduct as they advanced on the upper Missouri country, from Three Forks to the continental divide. This beautiful basin, a complex of wide, grassy valleys completely surrounded by mountain ranges, was well watered and stocked with large herds of buffalo. To seize and hold this country the Blackfeet were ready to fight against all opposition.
Although the Blackfeet had sent many war parties into this country as early as 1807, and small Piegan bands had sometimes gone up the Missouri to Three Forks to spend the summer during the 1820's, the Shoshoni and the Columbia Basin tribes still hunted there, and disputed possession with the hostile Blackfeet. And although the Blackfeet had destroyed Lisa's post in 1810 and had roughly handled Pilcher's men in 1822, the pesky mountain men still came in from the south to trap the beaver. These included parties led by Jim Bridger, Kit Carson, Tom Fitzpatrick, and William Sublette, who often joined with the Flatheads and Nez Percé to fight off large-scale Blackfoot attacks.