PART II: A Fur Trade Dynasty: From a Carignan Sallieres Soldier to the Wife of a Hudson’s Bay Company Chief Factor

 

Peter Skene Ogden

André "Old Pierre" Lagassé, Charles Lagassé, and François Rivet: Cousins and Brothers Forging a Fur Trade Legacy in the Columbia and Snake Country

The six-generation fur trade dynasty that began with Carignan-Salières soldier André Mignier dit Lagacé (1641–1727) in New France did not merely send voyageurs westward—it propelled a tight-knit network of Quebec-born kinsmen into the heart of the continent’s most remote and contested frontiers. By the early 19th century, that lineage had produced brothers André Lagassé (b. 19 August 1775, La Pocatière) and Charles Lagassé (b. ~1777), alongside their distant cousin François Rivet (b. 7 June 1754, St-Sulpice, L’Assomption). These three men—veteran steersmen, interpreters, guides, and freemen—moved in overlapping orbits with David Thompson, Alexander Ross, Peter Skene Ogden, and eventually tied their bloodline directly to Hudson’s Bay Company Chief Factor John Work. Their stories, drawn from notary contracts, Thompson and Alexander Henry the Younger’s journals, HBC archives, Snake Country expedition records, and Lewis and Clark rosters, reveal a shared world of canoe brigades, Salish winter camps, Blackfeet skirmishes, company mergers, and country marriages that helped open the Pacific Northwest to British commerce and Métis settlement.

Quebec Roots and Early Engagements

All three traced their skills to the same voyaging culture of the St. Lawrence lowlands. François Rivet, the eldest, came from a long line of Rivet voyageurs; his grandfather Pierre and father Nicolas-Pierre had paddled to Detroit, Michilimackinac, and the Illinois country in the 1730s–1740s. François himself signed multiple Montreal contracts in the 1790s (including one with Jacques Giasson in 1791 for three years “wherever required, Nord excluded”). By the late 1790s he had crossed into the Mississippi drainage and was trapping the upper Missouri among the Kansa, Omaha, Sioux, Arikara, Mandan, and Hidatsa.

André and Charles, sons of Charles Mignier dit Lagacé (1744–1819) and Marie Madeleine Aubé dit Aubert of the Kamouraska–La Pocatière corridor, followed the classic path. Charles signed his first known NWC contract on 28 March 1792 at Montréal (parish St-Cuthbert/Chicot) as gouvernail (steersman) and second gouvernail dans les terres for McTavish, Frobisher & Co., wages 900 livres, destination “dans le Nord.” André, two years older, secured a higher-status four-year contract on 19 April 1803 with Alexander Mackenzie & Co. (NWC) as guide et interprète bound for Red River, Swan River, and Lake Winnipeg, with double guide’s equipment and permission to route via Michilimackinac.

Parallel Paths with David Thompson and the Interior Trade

Their careers converged dramatically in the Rocky Mountain and Columbia theaters. Charles was with Thompson as early as April 1800 on the Upper Saskatchewan. In October 1800 Thompson dispatched him (with trade goods) to winter among the Kootenay (Ktunaxa) people—the first documented Euro-Canadian to do so. He and a companion (Le Blanc) are credited in some accounts as the first whites to cross the Rockies via Howse Pass that season. Charles returned to Rocky Mountain House in spring 1801, accompanied Thompson again in 1808–1810 through the Rockies and Kootenay House, supplied horses in the Saleesh (Flathead/Salish) country in spring 1810, briefly refused extra duty (listed as “deserter” 17 May 1810), then reappeared at Ilthkoyape (Kettle) Falls on 22 June 1811 during Thompson’s Columbia descent. He continued south with the expedition past Astoria in August 1811, wintered 1813–14 at Fort George (Astoria) as a milieu, served as bowsman on John Clarke’s 1814 brigade canoe to Fort William and Montreal, and re-engaged for Columbia service in 1812 (two-year term, free in Montreal 1814). After the 1821 NWC–HBC merger his contract transferred, but by 1822 he was a freeman and drops from HBC rolls—possibly the Charles who died ~1823.

André’s path complemented his brother’s. In the Red River brigade of 1800–01 (recorded in Alexander Henry the Younger’s journals) he appears as “voyageur, conductor” traveling with his wife, trading successfully in the Pembina Mountains (Hair Hills) alongside Joseph Dubois and others. Henry’s lists explicitly distinguish him from “the other of same surname, Charles Lagasse … who was with Thompson on the Upper Saskatchewan.” After his 1803 contract André continued as interpreter/guide in Henry and Thompson’s circles across Red River, Saskatchewan, and Missouri drainages. By the late 1800s he had reached the Columbia Plateau; oral tradition and secondary sources (Bruce McIntyre Watson’s Lives Lived West of the Divide, Métis genealogies, and family records) place him among the Salish/Spokane/Nez Perce near Kettle Falls. There, with a country wife identified variously as Emma or a Spokane/Salish/Flathead woman (sometimes called Therese in overlapping records, but distinct from Rivet’s wife), he fathered Josette (Suzette) Lagassé, born ~1809 near Kettle Falls—the future wife of John Work.

François Rivet entered the same Thompson orbit slightly later but no less intimately. After returning east with the Lewis and Clark keelboat party in 1805 (having wintered independently near Fort Mandan and entertained Mandan villagers by “dancing on his head”), he re-ascended the Missouri and by 1807 was among independent American/Canadian trappers in the Bitterroot Valley with John McClellan. He narrowly escaped a Blackfeet/Gros Ventre attack that killed eight companions in 1807–08, then traded ammunition-short with Thompson’s NWC party at the Kootenay River falls in winter 1808. In 1809 he is listed among the Métis freemen helping Thompson establish Salish House (Flathead Post) on the Clark Fork—alongside names like Finan McDonald, Michel Bordeaux dit Bourdon, and others. In June 1811, as Thompson descended from Spokane House toward Kettle Falls en route to Astoria, he passed the Rivet family camped “with four tents of Indians” along the trail—placing François, his Flathead/Salish wife Therese Tete Platte (a widow with daughter Julia), and young children in the exact Kettle Falls vicinity where André’s daughter Josette was born around the same time.

Snake Country Overlaps and the HBC Era

The 1821 merger brought them under one roof, and the Snake Country expeditions cemented their shared legacy. In 1824 François Rivet joined Alexander Ross’s brigade of ~140 men as interpreter; Ross’s journal notes him with “2 guns, 6 traps, 15 horses, 1 lodge.” When Peter Skene Ogden assumed command late that year, Rivet’s family—including step-daughter Julia (by then partnered with Ogden since ~1818, mother of Charles Ogden b. 1819)—traveled with the large party of 120. André “Old Pierre” Lagassé appears prominently in the same 1824 Ross journal and subsequent Ogden records: described as a seasoned freeman leader (“old Pierre at their head”), speaking for a group, and later referenced in contexts of horse disputes and brigade movements. (Note: while an Iroquois trapper named Pierre Tevanitagon is also called “Old Pierre” in some Snake journals, family oral tradition, Watson, and Métis sources consistently identify the Lagassé brother as the “Old Pierre” linked to the Columbia Plateau freemen and Josette’s paternity.) Charles, though by then a freeman, moved in the same Columbia–Snake orbit until his disappearance from rolls around 1822–23.

These expeditions were brutal “scorched-earth” campaigns to deplete beaver and deter American interlopers, yet they also mapped vast interior watersheds and sustained fragile alliances with Salish, Nez Perce, and other nations.

Country Families, Legacies, and Ties to John Work

Personal lives mirrored the trade’s cultural blending. François and Therese (married formally in 1839 at the Willamette mission) raised sons Antoine and Joseph (b. 1808–1810 in Montana territory) who became farmers on French Prairie, Oregon. Julia Rivet’s union with Ogden produced one of the most prominent HBC Métis families. André’s daughter Josette (1809–1896), born in the Kettle Falls/Salish country, married John Work (1792–1861), HBC chief factor whose Columbia District journals and Snake brigades further intersected the circle. Josette and John’s large family carried the Lagassé bloodline into British Columbia and Oregon settler society. Charles may have had children with a Flathead woman named Emme (Watson notes ambiguity, with oral tradition crediting “Pierre”/André as father of Josette and a son Pierre b. ~1815).

By the late 1820s–1830s the three men transitioned: Rivet transferred to Fort Colville (in charge briefly ~1832 at age ~75), retired 1838 to French Prairie—one of Oregon’s oldest settlers, godfather and community elder until his death 25/27 September 1852 at ~98. André and Charles fade from company rolls as freemen, their later years likely spent among Salish kin or Métis communities. Their collective presence helped stabilize NWC/HBC operations from the Rockies to the Willamette, facilitated Thompson’s epic surveys, supported Ogden’s Snake brigades, and seeded the Métis and settler families that followed.

Supporting Notes and Sources

• Contracts: BANQ notarial greffes (Charles 1792, André 1803, Rivet 1791); summarized in user’s blog and a-drifting-cowboy posts.
• Thompson/Henry Journals: Elliott Coues, New Light on the Early History of the Greater Northwest (1897), vol. I, pp. 28, 50–51 (André in Red River brigade; distinction from Charles); Thompson’s own travels (Peake, The Travels of David Thompson, vol. II); T.C. Elliott, Washington Historical Quarterly (1920) on Idaho journeys.
• HBCA Biographical Sheet: Charles Lagasse (entered ~1800, Columbia 1811–1821, Fort George 1813/14 as milieu, later boute, freeman post-1821); aliases Lagace, La Gassi, etc.
• Snake Country 1824: T.C. Elliott ed., Oregon Historical Quarterly vol. 14 (1913), pp. 371ff (Ross journal: “old Pierre” speaking, brigade details); William Kittson journal on Ogden 1824–25; E.E. Rich ed., Peter Skene Ogden’s Snake Country Journals (1950).
• Lewis & Clark and Rivet: Moulton ed., Journals; SPMHS article on Rivet (full bio confirming Mandan winter, return party, later NWC interpreter); Washington History Society “Old Rivet” (2004).
• Genealogy & Family: Watson, Lives Lived West of the Divide (2008) on Charles/Emme ambiguity and Josette paternity; user’s lineage to Carignan ancestor and Josette Work; Find a Grave and St. Paul mission records for Rivet (death 1852, sons Antoine/Joseph, step-daughter Julia m. Ogden).
• Secondary: Barry M. Gough on Henry; LeRoy R. Hafen, Mountain Men series; Metis Museum/Goulet profiles on Josette Work.

These three kinsmen—steersman, interpreter, and mountain man—embodied the dynasty’s westward thrust. From La Pocatière and L’Assomption contracts to Kettle Falls camps and Snake River brigades, they paddled, trapped, interpreted, and fathered the next generation across a continent. Their overlapping service with Thompson’s maps, Ogden’s ruthless efficiency, and Work’s later administration helped secure the Columbia District for the HBC and planted Métis roots that still echo in Oregon, Washington, and British Columbia today. In the end, the ripples from those La Prairie voyageur canoes reached the Pacific—and stayed. 

This revised essay expands PART I's foundation with deeper primary-source detail on the trio while preserving the wrap-around narrative from soldier ancestor to Josette Work’s marriage.

Thank you to Grok xA for this extraordinary conversation with added details on Francois Rivet. 

-- Drifting Cowboy