Peter Fidler's service to the Hudson's Bay Company spanned the three most important periods of the fur trade. He was the last of the company's winterers; later he faced the cutthroat opposition of the North West Company in its richest fur region; and in the last years of his life he helped to organize and sustain the Red River colony.

In 1788 nineteen-year-old Fidler left his native Derbyshire, signed on as a laborer with the Hudson's Bay Company, and traveled that summer to York Factory. A year later he accompanied William Tomison up the Saskatchewan River and spent the winter as "writer" at South Branch House, the position filled by David Thompson three years before. Philip Turnor, the company's surveyor since 1778, taught Fidler and Thompson the elements of navigation and cartography at Cumberland House during the winter of 1789–90. These months of intensive instruction were to be Turnor's most important contribution to the scientific knowledge of the continental interior. From that moment to the end of their active lives, his two students would keep detailed journals, map the vast extent of the British fur trade, and survey for new communities at the edges of its settled occupation.

The following year Fidler paddled with Turnor as far as the North West Company post of Ile à la Crosse, where they stayed as guests of the rival company and then pushed on to survey access to Great Slave Lake. In 1791–92 Fidler wintered with a band of Chipewyans, learning their language and sharing their way of life. The following winter he spent almost five months with the Peigans as they moved along the front ranges of the Rocky Mountains. The Hudson's Bay Company practice of sending young employees alone or in pairs to live with Native bands dated from Anthony Henday's inland journey from York Factory in 1754–55. By Fidler's time, trading posts extended European organization to the Athabaska region and the upper Saskatchewan watershed. These inland posts, rather than York Factory, were Fidler's points of departure, and his time with each band was much shorter than for previous generations of winterers, from Henday to Tomison. After 1793 the practice was discontinued.

Fidler spent the next nine years, from 1793 to 1802, at posts west of Lake Winnipeg and along the Saskatchewan River. Slowly he gathered information from his own surveys and from Native cartographers, which he compiled in a large map of the Plains. Fidler's own map, sent to the company's London Committee and then forwarded to Aaron Arrowsmith, has not survived; Arrowsmith probably discarded it when he copied its line of the Rockies south to Chief Mountain, and its delineation of the upper Missouri watershed, onto the 1802 version of his . Three years later Lewis and Clark consulted Arrowsmith's map on their way up the Missouri; they were dismayed that the map did not seem to show the river and the mountains accurately. Since they knew the source of Arrowsmith's information, the captains instantly doubted Fidler's "varacity." But the tracing of the Missouri watershed was conjectural, as clearly shown by Arrowsmith's dotted lines. And the Rockies that Fidler had in constant view from November 1792 to March 1793 do form a band of parallel ranges quite unlike the uplands and outcrops of the mountains to the south. Fidler's navigational skills as he made a running survey of the front ranges were in no way inferior to those of the Corps of Discovery.

Fidler spent four winters, from 1802 to 1806, at Lake Athabaska, sandwiched between posts of the North West Company and Alexander Mackenzie's XY Company. Although his winterer's knowledge of the Chipewyans' language and customs was an advantage, Fidler suffered brutal harassment from the other companies and traded few furs. The next few years spent at Cumberland House and Ile a la Crosse were more peaceful for him, although rivalry intensified and the resources of each company were strained by the need to manage trade across the continental divide as well as the difficult access to Athabasca.

The Hudson's Bay Company responded to the competition by cautiously following established routes and by attempting to diversify its trade (lumber, foodstuffs, and mining, as well as furs). Lord Selkirk's scheme of a colony at Red River seemed to fit well with this new policy: it could provide pemmican for brigades traveling long distances and it could be a center of farming and some manufacturing as well as administration of "northern" trade (the Athabaska and Saskatchewan districts). In 1812, after a year in England, Fidler led settlers from York Factory to Red River. The following year he began to survey lots, and from 1814 to 1816 he worked hard to keep the settlement going despite Metis hostility and opposition from the North West Company. In the summer of 1817 a treaty was signed extinguishing Aboriginal rights to the colony's surveyed territory in return for a yearly rent to be paid to the bands of Cree and Ojibwa who had formerly lived there. Fidler made a copy of the treaty and continued to survey lots in the colony. The settlers now numbered more than 200, and the colony's existence was no longer threatened.

Fidler spent the remaining years of his life at posts west of the colony. He was offered retirement with no diminution of his salary of £100 but preferred to continue as a clerk. He met George Simpson, just arrived from London as governor of Rupert's Land, and lived to see the collapse of the North West Company in 1821. Just before his death at Fort Dauphin, on December 17, 1822, Fidler formally married the mother of his fourteen children, of whom eleven survived him. His complicated will was broken in 1827 and his carefully amassed fortune of £1,900 was distributed among these survivors. The numerous descendants of Peter Fidler now form one of the leading Métis families of western Canada.

See also INDUSTRY: Hudson's Bay Company.