Thompson and M'Gillivray were back at Rocky Mountain House on the Saskatchewan for Christmas. Some time during 1800 their French-Canadian voyageurs are known to have crossed Howse Pass, the source of the North Saskatchewan, which was discovered by Duncan M'Gillivray and named after Joseph Howse of the North-West Company.

For several years after this Thompson was engaged in making surveys for the North-West Company in the valley of the Peace river and between the Saskatchewan and the Churchill. In 1806 we find him in the country south of the Peace, which was then in charge of that Jules Quesnel who was to accompany Fraser in 1808. Fraser, as we have seen, was already busy exploring the region between M'Leod Lake and Stuart Lake, and had laid his plans to descend the great river which he thought was Gray's Columbia. Now, while Thompson spent the winter of 1806-7 between the Peace and the North Saskatchewan, trading and exploring, he doubtless learned of Fraser's explorations west of the Rockies and of the vast extent of New Caledonia; and June 1807 saw him over the mountains on the Kootenay plains, where to his infinite delight he came upon a turbulent river, whose swollen current flowed towards the Pacific. 'May God give me to see where its waters flow into the ocean,' he ejaculated. This was, however, but a tributary of the long-sought Columbia. It was the river now called the Blaeberry. Thompson followed down the banks of this stream by a well-known Indian trail, and on June 30 he came to the Columbia itself. Although the river here flowed to the north, he must have known, from the deposits of blue silt and the turgidity of the current, that he had found at least an upper reach of the River of the West; but he could hardly guess that its winding course would lead him a dance of eleven hundred miles before he should reach the sea.

The party camped and built the boats they needed, and a fortnight later they were poling up-stream to the lake we to-day know as Windermere, where Thompson built a fort which he called 'Kootenai.' Here he spent the winter trading, and when the warm Chinook winds cleared away the snows, in April 1808, about the time Fraser was preparing to descend the Fraser river, he paddled up-stream to where the Columbia river has its source in Upper Columbia Lake. A portage of about a mile and a half brought him to another large river, which flowed southward. This stream—the Kootenay—led him south into the country of the Flatheads, then made a great bend and swept to the north. This was disappointing. Thompson returned to his fort on Windermere Lake, packed the furs his men had gathered, and retraced his trail of the previous year to Rocky Mountain House. He had undoubtedly found the River of the West, but he had learned nothing of its course to the sea.

During nearly all of 1809 Thompson was exploring the Kootenay river and its branches through Idaho and Montana. Still no path had he found to the sea. In 1810 he seems to have gone east for instructions from his company. What the instructions were we may conjecture from subsequent developments. Astor of New York, as we have seen, was busy launching his fur traders for operations on the Pacific. Piegan warriors blocked the passage into the Rockies by the North Saskatchewan; so Thompson in the autumn of this year ascended the Athabaska. Winter came early. The passes were filled with snow and beset by warriors. He failed to get provisions down from Rocky Mountain House; and his men, cut off by hostile savages from all help from outside posts, had literally to cut and shovel their way through Athabaska Pass while subsisting on short rations. The men built huts in the pass; some hunted, while others made snow-shoes and sleighs. They were down to rations of dog-meat and moccasins, and hardly knew whether to expect death at the hands of raiding Piegans or from starvation. On New Year's Day of 1811, when the thermometer dropped to 24° below zero, with a biting wind, Thompson was packing four broken-down horses and two dogs over the pass to the west side of the Great Divide. The mountains rose precipitously on each side; but when the trail began dropping down westward, the weather moderated, though the snow grew deeper; and in the third week of January Thompson came on the baffling current of the Columbia. He camped there for the remainder of the winter, near the entrance of the Canoe River. Why he went up the Columbia in the spring, tracing it back to its source, and thence south again into Idaho, instead of rounding the bend and going down the river, we do not know. He was evidently puzzled by the contrary directions in which the great river seemed to flow. At all events, by a route which is not clearly known, Thompson struck the Spokane river in June 1811, near the site of the present city of Spokane; and following down the Spokane, he again found the elusive Columbia and embarked on its waters. At the mouth of the Snake River, on July 9, he erected a pole, on which he hoisted a flag and attached a sheet of paper claiming possession of the country for Great Britain and the North-West Company. A month later, when Astor's traders came up-stream from the mouth of the Columbia, they were amazed to find a British flag 'waving triumphantly' at this spot. Unfortunately, Thompson's claim ignored the fact that both Lewis and Clark and the Astorians had already passed this way on their overland route to the Pacific.

From this point Thompson evidently raced for the Pacific. Within a week he had passed the Dalles, passed the mouth of the Willamette, passed what was to become the site of the Hudson's Bay Company's post of Fort Vancouver; and at midday of Monday, July 15, he swept round a bend of the mighty stream and came within sight of the sea. Crouched between the dank, heavy forests and the heaving river floods, stood a little palisaded and fresh-hewn log fur-post—Astoria. Thompson was two months too late to claim the region of the lower Columbia for the Nor'westers. One can imagine the wild halloo with which the tired voyageurs greeted Astoria when their comrades of old from Athabaska came tumbling hilariously from the fort gates—M'Dougall of Rocky Mountain House, Stuart of Chipewyan, and John Clarke, whom Thompson had known at Isle à la Crosse. But where was Alexander Mackay, who had gone overland with Mackenzie in 1793? The men fell into one another's arms with gruff, profane embraces. Thompson was haled in to a sumptuous midday dinner of river salmon, duck and partridge, and wines brought round the world. The absence of Mackay was the only thing that took from the pleasure of the occasion.

A party of the Astorians, as we have seen, had sailed round the Horn on the Tonquin; another party had gone overland from Mackinaw and St Louis. On the Tonquin were twenty sailors, four partners, twelve clerks, and thirteen voyageurs. She sailed from New York in September 1810. Jonathan Thorn, the captain, was a retired naval officer, who resented the easy familiarity of the fur traders with their servants, and ridiculed the seasickness of the fresh-water voyageurs. The Tonquin had barely rounded the Horn before the partners and the commander were at sixes and sevens. A landing was made at the mouth of the Columbia in March 1811, and eight lives were lost in an attempt to head small boats up against the tide-rip of river and sea. After endless jangling about where to land, where to build, how to build, the rude fort which Thompson saw had been knocked together. The Tonquin sailed up the coast of Vancouver Island to trade. On the vessel went Alexander Mackay to help in the trade with the coastal Indians, whom he was supposed to know. In spite of Mackay's warning that the Nootka tribes were notoriously treacherous and resentful towards white traders, Captain Thorn with lordly indifference permitted them to swarm aboard his vessel. Once when Mackay had gone ashore at Clayoquot, where Gray had wintered twenty years before, Thorn, forgetting that his ship was not a training-school, struck an old chief across the face and threw him over the rail. When Mackay heard what had happened, instead of applauding the captain's valour, he showed the utmost alarm, and begged Thorn to put out for the open sea. The captain smiled in scorn. Twenty Indians were welcomed on the deck the very next day. More came. At the same time the vessel was completely surrounded by a fleet of canoes. As if to throw the white men off all suspicion, the squaws came paddling out, laughing and chatting. Mackay in horror noticed that in the barter all the Indians were taking knives for their furs, and that groups were casually stationing themselves at points of vantage on the deck—at the hatches, at the cabin door, along the taffrail. Mackay hurried to the captain. Thorn affected to ignore any danger, but he nevertheless ordered the anchors up. Seeing so many Indians still on board, the sailors hesitated. Thorn lost his head and uttered a shout. This served as a signal for the savages, who shrieked with derisive glee and fell upon the crew with knives, hatchets, and clubs. Down the companionway tumbled the ship's clerk, Lewis, stabbed in the back. Over the taffrail headlong fell Mackay, clubbed by the Indians aboard, caught on the knives of the squaws below. The captain was so unprepared for the attack that he had no weapon but his pocket-knife. He was stunned by a club, pitched overboard, and literally cut to pieces by the squaws. In a moment the Tonquin was a shambles. All on deck were slaughtered but four, who gained the main cabin, and with muskets aimed through windows scattered the yelling horde. The Indians sprang from the ship and drew off, while the four white survivors escaped in a boat, and the Tonquin's sails flapped idly in the wind. Next morning the Indians paddled out to plunder what seemed to be a deserted ship. A wounded white man appeared above the hatches and waved them to come on board and trade. They came in hosts, in hordes, in flocks, like carrion-birds or ants overrunning a half-dead thing. Suddenly earth and air at Clayoquot harbour were rent with a terrific explosion, and the sea was drenched with the blood of the slaughtered savages. The only remaining white man, the wounded Lewis, had blown up the powder magazine. He perished himself in order to punish the marauders.

Had this story been known at Astoria when Thompson arrived, he would have found the Astorians in a thoroughly dejected condition. As it was, murmurs of discontent were heard. Here they had been marooned on the Columbia for three months without a ship, waiting for the contingent of the Astorians who were toiling across the continent.[[2]] Not thus did Nor'westers conduct expeditions. What Thompson thought of the situation we do not know. All we do know is that he remained only a week. On July 22, fully provisioned by M'Dougall, he went back up the Columbia post-haste.

One year later we find Thompson at Fort William reporting the results of his expedition to the assembled directors of the North-West Company. He had surveyed every part of the Columbia from its source to its mouth. And he was the first white man on its upper waters.

The War of 1812 had begun, and a British warship was on its way to capture Astoria. At the same time the Nor'westers dispatched an overland expedition to the Columbia. Among their emissaries went the men of New Caledonia, Alexander Henry (the younger) of Rocky Mountain House, Donald M'Tavish, and a dozen others who were former comrades of the leading Astorians. They succeeded in their mission, and in the month of October 1813 Astor's fort was sold to the North-West Company and renamed Fort George.