The report which Thompson made to his employers after his return to Grand Portage was of immense value to them. They now had a clear idea of the whole stretch of country from Sault Ste. Marie to the upper waters of the Missouri river, and were in a position to rearrange their trading houses to meet the needs of the time. Similar work remained to be done in the other regions to which the interests of the Company extended. But the same haste was not required, and the surveys could be pushed forward with less difficulty and expense in connection with what was the main object of the partners, that is the prosecution of the trade in furs. Thompson was therefore requested to undertake some of the actual work of trading, with freedom to make such journeys of exploration as he saw fit. The eight years following therefore mark a new period in his service with the North West Company, during which his activities carried him far and wide along the great waterways of the interior. Throughout these years he exercised, to the full, the qualities of mind and character which made him such a unique surveyor. His bulky note books were crammed with memoranda gathered with painstaking accuracy and checked with minute care. From time to time, where a less hurried visit to one of the more comfortable trading houses made it possible, he added his newly acquired information to the map which he had in hand. With each report that he made to Headquarters, the picture of the Great West gradually took shape. Its physical features were delineated; its wild life was noted and classified; its native populations, their numbers, their racial affinities and languages, their manners and customs were as far as possible described. This was indeed wizardry, as his ignorant French-Canadian and Indian followers imagined; but it was the wizardry of science, which, by the slow accumulation of ascertained facts, lays the whole world of nature at the feet of civilized man. In the summer of 1798, the attention of traders was largely directed to the western forest country, which lies beyond the divide separating the waters of the upper Saskatchewan from the basin of the Peace and Athabaska rivers. Twenty years before, Peter Pond had penetrated into this region as far as Lake Athabaska, and there established a post. At Lake Athabaska, ten years later, Roderick Mackenzie had built Fort Chippewyan, from which Sir Alexander had set out on his two famous voyages, the one down the Mackenzie to the Arctic, the other up the Peace to its headwaters and from thence across British Columbia to the Pacific. Apart, however, from the activity centred in Lake Athabaska, little had been done as yet to explore the possibilities of trade in what is now northern Alberta.