DEASE, PETER WARREN, HBC officer and Arctic explorer; b. 1 Jan. 1788 at Mackinac (Mackinac Island, Mich.), son of Dr John B. Dease, captain and deputy superintendent of the Indian Department, and Jane French, possibly a Roman Catholic Caughnawaga Mohawk; d. 17 Jan. 1863 at côte Sainte-Catherine (Montreal), Canada East.

Peter Warren Dease was named after Admiral Sir Peter Warren*, the captor of Louisbourg, Île Royale (Cape Breton Island) in 1745 and a paternal relative. Raised in Montreal, Dease at age 13 was engaged to the XY Company on 11 April 1801 at a salary of £75 plus food, lodging, and clothing for a six-year term in the “Indian or North West Country.” Following the amalgamation of the XY and North West companies in 1804, he was made a clerk in the North West Company and was posted to the Athabasca Department and then to the Mackenzie River District, being stationed at Fort Chipewyan and at posts on the Mackenzie River and north of Great Slave Lake. During the near warfare between the North West and Hudson’s Bay companies, Dease was with the party that waylaid Colin Robertson* at Grand Rapids below Île-à-la-Crosse about 28 June 1820.

With union of the two companies in 1821, Peter Warren Dease and his brother John Warren were appointed chief traders in the HBC; Peter Warren attended the first meeting of the Council of the Northern Department at Norway House in August 1821, where he was appointed to the Athabasca District. Early in 1823, Governor George Simpson* instructed Dease to undertake during the summer an exploration of the Finlay and other rivers west of the Rocky Mountains and parallel to the Mackenzie River. Dease received the instructions too late to start from Fort Chipewyan before spring break-up, with the result that Samuel Black* took charge of western explorations for 1824, and Dease was seconded to John Franklin*’s “Land Arctic Expedition” for outfits 1824–25, 1825–26, and 1826–27.

At Fort Chipewyan in May 1820 Dease had “promptly and kindly” provided information about the natives and geography to Franklin for his first expedition to the Arctic, and for the second expedition Franklin requested his services in obtaining provisions, managing Indian and voyageur support, and constructing a base on Great Slave Lake. During the winter of 1824–25 Dease procured fish from Great Slave Lake and helped make peace between the Copper Indians (or Yellowknives) and the Dogribs, so that they would hunt for the expedition. In July 1825 he superintended the construction of Fort Franklin on Great Bear Lake. Dease Bay (Dease Arm) on that lake and Dease River (which flows into it) commemorate his services to the Franklin expedition.

Dease continued in the Mackenzie River District with headquarters at Fort Good Hope from 1827 until 1830. He was promoted chief factor 23 Jan. 1828, a reward for his aid to Franklin, and in July 1830 he was appointed to Fraser Lake in New Caledonia (British Columbia).

In the spring of 1831 Dease assumed sole charge of the New Caledonia District from William Connolly*, and he transferred his station to Fort St James on Stuart Lake. The district now showed large profits, said to be £8,000 in 1834. Dease was popular among his men as he was “most amiable, warm hearted, sociable.” He brightened life at Fort St James with feasts of “roasted bear, beaver and marmot” and games of chess, backgammon, and whist; he played remarkably well on the violin and flute “for the fort’s musical soirees.” He was praised by his superiors for having established a new order of things at Fort St James, particularly in the introduction of cattle from Fort Vancouver (Vancouver, Wash.) and the encouragement of farming. In 1835, with a leave of absence, he was replaced by Peter Skene Ogden*.

In June 1836 the council assigned Dease to command the Arctic exploring expedition launched by the HBC to fill in the gaps left by the expeditions of naval officers Franklin, Frederick William Beechey*, and George Back* in the search for the northwest passage. George Simpson’s young cousin, Thomas Simpson, who had joined the HBC in 1829 and had recently caused a disturbance among the Métis at Fort Garry (Winnipeg), was made second-in-command with responsibility for surveying and scientific investigations. The expedition, with 12 men, was to explore westward from the mouth of the Mackenzie River and eastward from Franklin’s Point Turnagain on the Kent Peninsula.

Dease was joined at Fort Chipewyan on 1 Feb. 1837 by Simpson, who had made an astounding overland trip of 1,277 miles from Red River in a mere 62 days. They left the post on 1 June 1837, and at Fort Resolution on Great Slave Lake Dease vaccinated all the young natives. They reached the mouth of the Mackenzie River on 9 July. By 23 July they had progressed to Return Reef (Alaska), Franklin’s farthest west point in 1826, which he had not attained until mid August. But on 31 July they had to abandon the sea because of ice. The following day Simpson set out overland from “Boat Extreme” on the remaining 60 miles to Barrow Point, which the Beechey expedition had reached from the west. Borrowing a native oomiak at Dease Inlet, Simpson reached Barrow Point on 4 August where he took possession of their discoveries for Britain. The reunited party reached the mouth of the Mackenzie on 17 August and Fort Norman on 4 September. There they received instructions to explore east of the Coppermine River in 1838. From Fort Norman Simpson wrote of being “sore” at not being given command, and that winter, from the winter quarters built for them at Fort Confidence on Great Bear Lake, wrote that “Dease is a worthy, indolent, illiterate soul, and moves just as I give the impulse,” and that since he himself had “the exclusive honour of . . . uniting the Arctic to the Western Ocean” he felt entitled to promotion to chief trader.

The expedition of 1838 was disappointing because of the “extraordinary duration of the ice.” In June they ascended the Dease River and crossed the Dismal Lakes which Simpson had discovered during a 95-mile exploration of seven days in March and April. Reaching the mouth of the Coppermine River on 1 July, they were imprisoned by ice until 7 July, Dease using the time to collect plants. After a “desperate” struggle with the “same cold obdurate foe,” they rounded Cape Barrow on 29 July. Their boats were finally stopped on 9 August at Cape Flinders, three miles south of Franklin’s 1821 encampment at Point Turnagain. Government expeditions were expected to turn back on 20 August, a result of the disaster of Franklin’s first journey, but Simpson proceeded on foot with five HBC servants and two Indians. When he returned to Dease on 29 August he had traced 100 miles of coast and had named Victoria Land (Island) and Cape Pelly. The party returned to the Coppermine River on 3 September, reaching their winter quarters across “the barren grounds” on 14 September. Simpson was soon blaming their failure on Dease’s caution, adding that Dease, whose family had joined him in late August 1837, was “so much engrossed with family affairs, that he is disposed to risk nothing.” To his brother, Simpson complained that he was “like Sinbad the sailor, hampered with an old man on my back.” Dease, in truth, was concerned about their provisions and the possibility of being recalled from the expedition that autumn.

Dease and Simpson spent a second winter at Fort Confidence and in 1839 they again attempted to explore to the eastward. From the mouth of the Coppermine River Simpson explored the Richardson River which had been discovered in 1838, and on 3 July the sea ice opened. But their boats only attained Cape Barrow on 18 July. Ten days later they doubled Cape Alexander (near Simpson’s farthest of 1838) and discovered Dease and Simpson Strait (now Simpson Strait) separating King William Island from the mainland. It led to the mouth of the Great Fish River (Back River). On 16 August they reached Montreal Island where they discovered a cache left by George Back. Thus, they had filled in the gaps left by the explorations of Franklin and the voyages of Beechey and Back. It remained to determine the relationship of the Boothia Peninsula, separating them from the Gulf of Boothia, to the continent. Although it was now time to turn back, they reached, and named, Cape Britannia on 17 August; Simpson also made a run of 40 miles to the northeast of Cape John Ross, where he named his farthest point the Castor and Pollux River, after the expedition’s two boats. There he asserted (erroneously because of seriously restricted visibility) that five miles to the east the coastline turned south, thus denying the existence of the Isthmus of Boothia. En route back to the Coppermine, the expedition explored late in August the south coast of King William Island. They reached the Coppermine on 16 September after winter had set in in earnest. But they had completed the longest voyage performed in boats on the polar sea, and they had more than fulfilled the mandate of the company’s instructions.

After “boisterous and inclement” weather they reached Fort Simpson (District of Mackenzie) on 14 October. There Simpson completed his “Narrative of the Expedition” before departing for Upper Fort Garry (Winnipeg) on 2 December. He had requested permission to make a new expedition in the Gulf of Boothia himself (“Fame I will have but it must be alone,” free from “the extravagant and profligate habits of half-breed families”) but Governor Simpson was still unwilling to give his impetuous cousin independent command and Dease had taken leave. In June 1840 Simpson set out for England to ensure he received major credit for their discoveries and to appeal for the new expedition. En route to St Paul (Minn.), moody and overwrought, he killed two of his four Métis companions, and then, it is assumed, committed suicide.

In three summers Dease and Simpson had explored the Arctic coast through 60 degrees of latitude at a cost to the HBC of £1,000 and, except for the transit of the Boothia Peninsula, they had completed the long-sought survey of the northwest passage. That Simpson was the more daring is beyond doubt, but Dease’s logistical abilities in organizing supplies, recruiting and maintaining discipline among his men, keeping peace among the natives, and managing the swift movement with a simplicity of equipment while living off the land in so far as possible assured the success of these arduous expeditions despite the disappointments of 1838. Governor George Simpson had been more than justified in refusing to give his erratic and self-seeking cousin independent command.

Dease, who was granted furlough for 1840–41 to seek medical attention in England for eye trouble, was at Norway House for the council in June 1840, and then at Red River, where, already a grandfather (he had had four sons and four daughters), he married his fur trade wife, Élizabeth Chouinard, a Métis, on 3 Aug. 1840. Dease and Simpson had each been granted a pension of £100 a year by Queen Victoria in June, “for their exertions towards completing the discovery of the North West Passage,” and it was rumoured that Dease would be knighted, “which,” said Letitia Hargrave [Mactavish*], “diverts the people here as they say Mrs Dease is a very black squaw & will be a curious lady.” However, Dease, “with that modesty which was part of his nature,” declined the knighthood. He was introduced to the HBC Committee in London in October. His furlough was extended until his retirement from active duty on 1 June 1843.

Dease settled on a farm at côte Sainte-Catherine near Montreal in early 1841. He was joined by his family from Red River, and it was said by James Keith*, an HBC chief factor, that he was governed “by his Old Squaw & Sons. She holding the Purse strings & they spending the Contents par la Porte et par les fenetres.” At côte Sainte-Catherine, Dease had 20 years of “comfortable and much respected” retirement. Three sons predeceased him and the fourth died in 1864.

George Simpson’s perceptive remarks in his famous “Character Book” of 1832 remain the best commentary on Peter Warren Dease: “Very steady in business, an excellent Indian Trader, speaks several of the Languages well and is a man of very correct conduct and character. Strong vigorous and capable of going through a great deal of Severe Service but rather indolent, wanting in ambition to distinguish himself in any measure out of the usual course .... His judgement is sound, his manners are more pleasing and easy than those of many of his colleagues, and altho’ not calculated to make a shining figure, may be considered a very respectable member of the concern.”

William R. Sampson