In company with Jussomme and McCrachan, Thompson then paid a visit to each of the five villages in turn. These, he found, were all built alike of domelike huts constructed of mud plastered over a framework of wood, each with an aperture in the centre of the roof to carry off the smoke of the fire and admit light to the solitary chamber of the dwelling. In front of each house stood a porch made of stretched bison skins, affording an approach to a doorway large enough to admit a horse. Passing the door, one entered a circular chamber about forty feet across, and, from the earthen floor to the aperture in the roof, eighteen or twenty feet in height. To the left of the doorway, sat the master of the house on a couch covered with buffalo robes. Before him was the fire, built in a circular space hollowed out of the floor, and surrounded by vessels of native pottery containing maize and boiled meat, the food of the household. Around the walls were a series of frame bunks about three feet from the ground, each of them enclosed by hides except for the front and made comfortable by a soft buffalo robe. To the right of the entrance were the stalls for the two or three horses which belonged to the household, to which every evening they were led back after pasturing on the plains. In the smallest of these villages, Thompson counted thirty-one such huts, in the largest one hundred-and-thirteen, each hut containing a family of from eight to ten souls.

Surrounded as they were by fierce and violent enemies, the Mandans had constructed their villages with an eye to defence rather than to comfort. For this purpose a site was selected on elevated ground, so that no attack could be made from above. The houses were then built irregularly without regard for streets, and the whole village surrounded by a stockade of timbers at least twelve feet in height. On more than one occasion, Thompson learned, the Sioux had taken advantage of a dark and stormy night to approach the villages and fire the palisades. But the flames had no power to destroy the earthen houses; there were no straight streets down which the enemy could shoot; and, as a regular siege was beyond the power of any of their foes, the Mandans had hitherto escaped destruction.

The tribe, when Thompson visited them, were already acquainted with the use of iron. Their flint-tipped spears and arrows they gladly laid aside, when they could, for a long spear, headed with a flat iron bayonet nine or ten inches in length. Thus far, however, they had been visited only irregularly by traders; and so had but few guns among them. Iron was so precious for purposes of war that it had not yet come into common use for agriculture. Their ploughs were made of the shoulder blade of a deer or bison, neatly fastened by thongs to a handle. For hoes, they used pointed sticks hardened in the fire. A council of old men allotted to each family its portion of ground in the rich alluvial of the river bottom. From this they were able with their rude implements to raise a sufficient quantity of the maize, pumpkins, beans, and melons which were native to America.

Thompson was anxious to find out the origin of this interesting people, for they had not been many years on the banks of the Missouri. Their traditions, however, went back no further than the days of their great-great-grandfathers. These, they said, had dwelt to the eastward, possessing the rich flats about the upper waters of the Red river and the Mississippi. There the wild rice grew in abundance and the deer were in plenty, though the horse and the buffalo were unknown. On all these streams they had villages and cultivated the ground as at present from before the memory of man.

The Sioux to the south of their ancient home were their enemies, but, armed only with stone-headed spears and arrows, could do them little harm. To the north-east, in the depths of the gloomy forest, dwelt the Chippewas, who were likewise powerless to hurt them. But the day came when the Chippewas, armed by the white traders with guns, ironheaded arrows, and spears, silently collected under cover of the forest, and sallied out to harry their villages with fire, and cut off their men as they were scattered in hunting parties far and wide. Hard pressed by the attacks of an enemy whom they could not resist, they gave way from point to point until they arrived at the banks of the Missouri; and thus put the width of the great plains between them and their implacable foes.

Having made friends with the natives and taken the observations necessary to determine the position of their villages, Thompson prepared to depart. As the Mandans dwelt in the territory of the United States, and it was contrary to the treaty of 1794 for a British company to plant trading posts among them, commerce was possible only if they were willing to make the journey to McDonnell's house to trade. Accordingly a chief in the prime of life, together with four young warriors, was selected to accompany Thompson on the trip home. These were joined by an old man and his squaw, who said that they wished to see the houses of the white men before they died. But the heights of the Missouri were too much for the aged couple, and they dropped out. Fourteen days of storm and tempest on the open plain sufficed to kill the spirit of two of the warriors, and they also dropped out. With the remainder, Thompson arrived at Assiniboine House on the 3rd of February, 1798. Unfortunately, the attempt to open up trade with the Mandans turned out to be unsuccessful. The journey was long and difficult in winter; and, in summer, the Sioux were active and cut off parties who tried to make the passage across their land so that the Mandan villages proved to be beyond the reach of the merchants from Canada.

At McDonnell's house, Thompson prepared the maps and notes of his survey to be sent by the next convoy to headquarters at Grand Portage. He then took leave of his hospitable friend, and set forth on his explorations up the Red river. With three French Canadians and an Indian guide, he started down the Assiniboine, hauling his baggage and provisions by dog sleds on the ice. The tedious windings of the stream and the ever increasing depth of snow made progress difficult. Nevertheless, by the 7th of March he had reached the junction of the Assiniboine and the Red rivers, where the city of Winnipeg now stands. He then turned up the Red river, and in six days' travel came to the international boundary, beyond which it was his duty to warn all traders that they were trespassing in the territory of the United States.

By the 25th of March he had worked his way south as far as the post of Baptiste Cadotte, which was situated on a tributary of the Red river, near the present site of the town of Red Lake Falls. From this point he purposed to cross the height of land to the western end of Lake Superior. Could he do it before the break-up of winter, and while the mantle of snow still lay on the ground to give passage to his dogs? He had, it will be remembered, no experience of southern latitudes. His last winter had been spent by the shore of Reindeer lake, where the ice stood firm till a windstorm broke it up on the fifth day of July. Cadotte warned him that the season was too far advanced; but he took the risk.

On the 27th of March he began his his journey eastward up the Clearwater river into Minnesota, picking up a guide from some Chippewas whom he found on the way. As the day wore on, the rays of the sun increased in power, and walking became difficult in the thawing snow. The night was mild, and the following morning the guide took care to break his snow-shoes that he might have an excuse for returning to camp. The day was wasted, while Thompson waited impatiently for another guide to be sent to take the place of the first. At sundown a storm came on with thunder, lightning, and rain, which continued the night through and far into the next day. The snow was now so heavy that progress was impossible. The continuous rains had soaked the clothes and the baggage of the party through and through. The fourth day opened with gusts of hail and sleet. The country before them was like a lake, and Thompson was compelled to admit himself beaten. Splashing and stumbling through the bush and along the treacherous ice of the river, the party struggled to make their way back to the protecting shelter of Cadotte's roof. But their baggage was too much for them, and they had to give in. Finally Thompson with one man, travelling light, pressed forward to the post for help; and by the afternoon of the second day the weary travellers were brought safely into camp.

When the rivers were finally clear of ice, Thompson, with his three Canadians and a native woman, made a fresh start, this time by canoe and with dried provisions to last for twelve days. They had first to battle their way against the current of Clearwater river, to the portage which brought them to Red lake. The country was everywhere soaked with water, so that at night they were forced to cut down trees and sleep on the branches. Red lake, they found, was still covered with patches of broken ice. Hauling and paddling their canoe in turn they crossed the lake, and entered an immense area of pond and marsh to the south. Everywhere stretched beds of wild rice, the haunt of innumerable geese, duck, and loon. With infinite toil they made their way from lake to lake and brook to brook, until after five days in the marsh they arrived at Turtle lake.