It was on Wednesday, June 3, 1789, that Alexander Mackenzie's little flotilla of four birch-bark canoes set out across Lake Athabaska on its way to the north. In Mackenzie's canoe were four French-Canadian voyageurs, two of them accompanied by their wives, and a German. Two other canoes were filled with Indians, who were to act as guides and interpreters. At their head was a notable brave who had been one of the band of Matonabbee, Hearne's famous guide. From his frequent visits to the English post at Fort Churchill he had acquired the name of the 'English Chief.' Another canoe was in charge of Leroux, a French-Canadian in the service of the company, who had already descended the Slave river, as far as the Great Slave Lake. Leroux and his men carried trading goods and supplies.

The first part of the journey was by a route already known. The voyageurs paddled across the twenty miles of water which here forms the breadth of Lake Athabaska, entered a river running from the lake, and followed its winding stream. They encamped at night seven miles from the lake. The next morning at four o'clock the canoes were on their way again, descending the winding river through a low forest of birch and willow. After a paddle of ten miles, a bend in the little river brought the canoes out upon the broad stream of the Peace river, its waters here being upwards of a mile wide and running with a strong current to the north. On our modern maps this great stream after it leaves Lake Athabaska is called the Slave river: but it is really one and the same mighty river, carrying its waters from the valleys of British Columbia through the gorges of the Rocky Mountains, passing into the Great Slave Lake, and then, under the name of the Mackenzie, emptying into the Arctic.

In the next five days Mackenzie's canoes successfully descended the river to the Great Slave Lake, a distance of some two hundred and thirty-five miles. The journey was not without its dangers. The Slave river has a varied course: at times it broadens out into a great sheet of water six miles across, flowing with a gentle current and carrying the light canoes gently upon its unruffled surface. In other places it is confined into a narrow channel, breaks into swift eddies and pours in boiling rapids over the jagged rocks. Over the upper rapids of the river, Mackenzie and his men were able to run their canoes fully laden; but lower down were long and arduous portages, rendered dangerous by the masses of broken ice still clinging to the banks of the river. As they neared the Great Slave Lake boisterous gales from the north-east lashed the surface of the river into foam and brought violent showers of rain. But the voyageurs were trained men, accustomed to face the dangers of northern navigation.

A week of travel brought them on June 9 to the Great Slave Lake. It was still early in the season. The rigour of winter was not yet relaxed. As far as the eye could see the surface of the lake presented an unbroken sheet of ice. Only along the shore had narrow lanes of open water appeared. The weather was bitterly cold, and there was no immediate prospect of the break-up of the ice.

For a fortnight Mackenzie and his party remained at the lake, skirting its shores as best they could, and searching among the bays and islands of its western end for the outlet towards the north which they knew must exist. Heavy rain, alternating with bitter cold, caused them much hardship. At times it froze so hard that a thin sheet of new ice covered even the open water of the lake. But as the month advanced the mass of old ice began slowly to break; strong winds drove it towards the north, and the canoes were presently able to pass, with great danger and difficulty, among the broken floes. Mackenzie met a band of Yellow Knife Indians, who assured him that a great river ran out of the west end of the lake, and offered a guide to aid him in finding the channel among the islands and sandbars of the lake. Convinced that his search would be successful, Mackenzie took all the remaining supplies into his canoes and sent back Leroux to Chipewyan with the news that he had gone north down the great river. But even after obtaining his guide Mackenzie spent four days searching for the outlet It was not till the end of the month of June that his search was rewarded, and, at the extreme south-west, the lake, after stretching out among islands and shallows, was found to contract into the channel of a river.

The first day of July saw Mackenzie's canoes floating down the stream that bears his name. From now on, progress became easier. At this latitude and season the northern day gave the voyageurs twenty hours of sunlight in each day, and with smooth water and a favouring current the descent was rapid. Five days after leaving the Great Slave Lake the canoes reached the region where the waters of the Great Bear Lake, then still unknown, drain into the Mackenzie. The Indians of this district seemed entirely different from those known at the trading posts. At the sight of the canoes and the equipment of the voyageurs they made off and hid among the rocks and trees beside the river. Mackenzie's Indians contrived to make themselves understood, by calling out to them in the Chipewyan language, but the strange Indians showed the greatest reluctance and apprehension, and only with difficulty allowed Mackenzie's people to come among them. Mackenzie notes the peculiar fact that they seemed unacquainted with tobacco, and that even fire-water was accepted by them rather from fear of offending than from any inclination. Knives, hatchets and tools, however, they took with great eagerness. On learning of Mackenzie's design to go on towards the north they endeavoured with every possible expression of horror to induce him to turn back. The sea, they said, was so far away that winter after winter must pass before Mackenzie could hope to reach it: he would be an old man before he could complete the voyage. More than this, the river, so they averred, fell over great cataracts which no one could pass; he would find no animals and no food for his men. The whole country was haunted by monsters. Mackenzie was not to be deterred by such childish and obviously interested terrors. His interpreters explained that he had no fear of the horrors that they depicted, and, by a heavy bribe, consisting of a kettle, an axe, and a knife, he succeeded in enlisting the services of one of the Indians as a guide. That the terror of the Far North professed by these Indians, or at any rate the terror of going there in strange company, was not wholly imaginary was made plain from the conduct of the guide. When the time came to depart he showed every sign of anxiety and fear: he sought in vain to induce his friends to take his place: finding that he must go, he reluctantly bade farewell to his wife and children, cutting off a lock of his hair and dividing it into three parts, which he fastened to the hair of each of them.

On July 5, the party set out with their new guide, and on the same afternoon passed the mouth of the Great Bear river, which joins the Mackenzie in a flood of sea-green water, fresh, but coloured like that of the ocean. Below this point, they passed many islands. The banks of the river rose to high mountains covered with snow. The country, so the guide said, was here filled with bears, but the voyageurs saw nothing worse than mosquitoes, which descended in clouds upon the canoes. As the party went on to the north, the guide seemed more and more stricken with fear and consumed with the longing to return to his people. In the morning after breaking camp nothing but force would induce him to embark, and on the fourth night, during the confusion of a violent thunder-storm, he made off and was seen no more.

The next day, however, Mackenzie supplied his place, this time by force, from a band of roving Indians. The new guide told him that the sea was not far away, and that it could be reached in ten days. As the journey continued the river was broken into so many channels and so dotted with islands, that it was almost impossible to decide which was the main waterway. The guide's advice was evidently influenced by his desire to avoid the Eskimos, and, like his predecessor, to keep away from the supposed terrors of the North. The shores of the river were now at times low, though usually lofty mountains could be seen about ten miles away. Trees were still present, especially fir and birch, though in places both shores of the river were entirely bare, and the islands were mere banks of sand and mud to which great masses of ice adhered. An observation taken on July 10 showed that the voyageurs had reached latitude 67° 47' north. From the extreme variation of the compass, and from other signs, Mackenzie was now certain that he was approaching the northern ocean. He was assured that in a few days more of travel he could reach its shores. But in the meantime his provisions were running low. His Indian guide, a prey to fantastic terrors, endeavoured to dissuade him from his purpose, while his canoe men, now far beyond the utmost limits of the country known to the fur trade, began to share the apprehensions of the guide, and clamoured eagerly for return. Mackenzie himself was of the opinion that it would not be possible for him to return to Chipewyan while the rivers were still open, and that the approach of winter must surprise him in these northern solitudes. But in spite of this he could not bring himself to turn back. With his men he stipulated for seven days; if the northern ocean were not found in that time he would turn south again.

The expedition went forward. On July 10, they made a course of thirty-two miles, the river sweeping with a strong current through a low, flat country, a mountain range still visible in the west and reaching out towards the north. At the spot where they pitched their tents at night on the river bank they could see the traces of an encampment of Eskimos. The sun shone brilliantly the whole night, never descending below the horizon. Mackenzie sat up all night observing its course in the sky. At a quarter to four in the morning, the canoes were off again, the river winding and turning in its course but heading for the north-west. Here and there on the banks they saw traces of the Eskimos, the marks of camp fires, and the remains of huts, made of drift-wood covered with grass and willows. This day the canoes travelled fifty-four miles. The prospect about the travellers was gloomy and dispiriting. The low banks of the river were now almost treeless, except that here and there grew stunted willow, not more than three feet in height. The weather was cloudy and raw, with gusts of rain at intervals. The discontent of Mackenzie's companions grew apace: the guide was evidently at the end of his knowledge; while the violent rain, the biting cold and the fear of an attack by hostile savages kept the voyageurs in a continual state of apprehension. July 12 was marked by continued cold, and the canoes traversed a country so bare and naked that scarcely a shrub could be seen. At one place the land rose in high banks above the river, and was bright with short grass and flowers, though all the lower shore was now thick with ice and snow, and even in the warmer spots the soil was only thawed to a depth of four inches. Here also were seen more Eskimo huts, with fragments of sledges, a square stone kettle, and other utensils lying about.