From 1836 to 1839, Simpson was involved in an expedition to chart the
Arctic coast of
Canada in order to fill two gaps left by other expeditions in search of the
Northwest Passage. The expedition was headed by
Peter Warren Dease, a chief factor of the HBC. Simpson was the junior officer, but Dease ceded most of the responsibility to him. Several writers present Simpson as an ambitious and over-confident young man, whereas Dease was twenty years older, experienced in
Arctic exploration and efficient but perhaps under-confident. Simpson and Dease were accompanied by ten more men, including
canoemen James McKay and George Sinclair. The expedition was organized by the HBC rather than the British
Royal Navy, which sponsored most expeditions pressing the Northwest Passage. They were to descend the
Mackenzie River to the
Arctic Ocean, turn west and close the gap between
John Franklin's 1826 furthest-west and
Frederick William Beechey's furthest-east at
Point Barrow. The next summer they were to go down the
Coppermine River, repeat Franklin's 1821 route east to
Cape Turnagain and continue along the unknown coast at least to the mouth of the
Back River, which had been reached overland in 1834. They spent the winter of 1836 at
Fort Chipewyan, where they built two boats. The party left on 1 June, and a month later reached the mouth of the
Great Bear River. There they detached four men to go upriver to the
Great Bear Lake and build winter quarters at
Fort Confidence while the rest went down the Mackenzie to the Arctic, which they reached on 9 July. They then traveled west along the coast past Franklin's Return Reef until they were blocked by ice at Boat Extreme, about east of Point Barrow. Simpson and five men continued on foot and reached Point Barrow on 4 August. They returned to Fort Confidence on 25 September. At this point the north coast had been mapped from the
Bering Strait to the mouth of the Coppermine. Early in the year, Simpson went overland to find the upper Coppermine River. In the summer they descended the Coppermine, which was full of meltwater, and reached the still-frozen Arctic. They waited two weeks for the ice to clear and began working slowly east. On 20 August they were blocked by ice a few miles from Franklin's Point Turnagain on the
Kent Peninsula. Dease stayed behind with the boats and Simpson walked about east to a place he called Point Alexander. To the north he saw and named
Victoria Land. To the east he saw open water in
Queen Maud Gulf. He returned to Dease and the frozen-in boats. A few days later the ice suddenly cleared and they had an easy sail back to the Coppermine. They had gone only a little further than Franklin. It was a better year for ice. The party followed the same route, passed Point Turnagain and Cape Alexander, sailed for the first time the
Dease Strait and the Queen Maud Gulf, found the
Adelaide Peninsula and
Simpson Strait to its north and reached
Chantrey Inlet, where McKay and Sinclair had been in 1834. At
Montreal Island they found a cache left by
George Back in 1834. Leaving Chantrey Inlet they were struck by a
gale that lasted four days. Fifty miles northeast they turned back at the
Castor and Pollux River. Returning, they followed the south shore of
King William Island to a point they called Cape Herschel, where the coast turned north, then followed the south shore of Queen Maud Gulf and the south shore of Victoria Island. It had been the longest boat voyage ever made in Canadian Arctic waters. At this point the entire Arctic coast had been roughly mapped from the Bering Strait to beyond Chantrey Inlet. The remaining problems were the possibility of a water route from Chantrey Inlet to the
Gulf of Boothia and the huge rectangular area north of the coast and south of the
Parry Channel. The party returned to the
Great Slave Lake in September of that year, and from there Simpson drew up a letter to the directors of the HBC describing the results of the expedition, which was published in many newspapers of the day. He also transmitted a plan for an expedition to complete further exploration of the coast between the
Fury and Hecla Strait and the eastern limits of his previous explorations. To attend to preparations for this new expedition, Simpson immediately left for the
Red River Colony, making the entire journey in sixty-one days, arriving on 2 February 1840. The annual canoes from Canada to the settlement in June of that year brought no word of the reception of his exploits, or authorization to continue exploration, as word had not reached England in time to reply at that opportunity. Without authorization from the directors, Simpson had no authority to arrange another expedition. Instead of waiting for an entire year for word, he decided to return to Britain in person. == Death and investigation ==