The Rocky Mountain Ram
In the fall of 1800, David Thompson and his new mixed-blood Cree wife Charlotte Small were posted to Rocky Mountain House, the North West Company establishment furthest up the Saskatchewan River. In early October he traveled up the Red Deer River to meet another Kootenai band who had crossed the Continental Divide. After trading with this group, Thompson sent two of his voyageurs back west with the tribal party in anticipation of the establishment of a trade house in the new Columbia District.
East Slope of the Rockies
Company partner Duncan McGillivray arrived at Rocky Mountain House soon after the Kootenais and two voyageurs departed, and proceeded to set in motion an ambitious North West plan to make Alexander Mackenzie's transcontinental fur business a reality. McGillivray and Thompson rode south to visit the same Blackfeet camps where Thompson had wintered as a teenager. They asked Piegan elders for permission to bring Iroquois free trappers onto the east slope of the Rockies, then continued up the Bow River for a closer look at the mountains they would have to traverse to reach the Columbia. Both of these furmen studied natural history, and reveled in the wealth of mammals they saw in the upper Bow drainage. When McGillivray shot a large Rocky Mountain bighorn sheep, Thompson carefully recorded the ram's horn and body measurements in his journal.
In the spring of 1801 the Nor'Westers made a serious attempt to cross the Rocky Mountains and establish their first post in the Columbia country. With Duncan McGillivray incapacitated by rheumatism, agent James Hughes took charge of the small party; Thompson served as the surveyor and second in command. Foundering under the unfamiliar difficulties of mountain travel, the group never made it to the Continental Divide, and in his report to the Company partners Thompson explained both the trials of spring runoff and the necessity of an expert guide. He made it clear he would learn from the experience, and was eager to try again.
McGillivray, meanwhile, returned to the east, and in time delivered a dried Rocky Mountain sheep skin to Dr. Samuel Mitchill's Lyceum of Natural History in New York. A keen follower of western exploration, Mitchill had recently taken over editorship of the Philadelphia-based scientific journal Medical Repository from Jefferson's close friend and Corps of Discovery medical advisor, Dr. Benjamin Rush.
Mr. Savage was Edward Savage (1761-1817), a painter and engraver who worked in Philadelphia. Ovis Ammon, Pudu,...Strepsiceros: Ovis is Latin for sheep. Ovis ammon and O. strepsiceros are native to Eastern Europe and Central Asia; O. pudu was found on the coasts of South America. Mr. Pennant was Thomas Pennant (1726-1798), a British naturalist whose Arctic Zoology (1785-887) was among the first studies of North American mammals.
In an 1803 issue of Medical Repository, Mitchill published Duncan McGillivray's "Account of the Wild North-American Sheep." McGillivray's letter described how during an expedition up the Bow River with Thompson, he had broken off with an Indian guide to have a shot at a small herd of animals that the Cree called "ugly rein deer." While Thompson was busy taking a meridian altitude, the two hunters brought down four mountain rams in all. Thanks to Thompson's observations, McGillivray was able to include an exact latitude and longitude for the spot where he had taken the sheep that ended up in Dr. Mitchill's museum.
Thomas Jefferson certainly subscribed to Medical Repository. If he didn't see the article immediately, an 1803 letter from a friend called the president's attention to McGillivray's mention of the Missouri and Saskatchewan Rivers in the Repository account. No matter when Jefferson read the story, he would have gleaned details from it about the natural history of a new western mammal, British movements on the east slope of the Rockies, and the surveying skills of David Thompson.
The Corps of Discovery
After Thompson's 1801 attempt to cross the Divide, fur trade rivalries and the Napoleonic wars sidetracked North West Company efforts to establish trade in the Columbia District. These same elements helped Thomas Jefferson to acquire the Louisiana Territory and push ahead with his own long-held plans to follow the Great River of the West to the Pacific.
When Lewis and Clark worked their way up the Missouri in the fall of 1804, they had in their possession a copy of Thompson's "Bend of the Missouri" map. After the captains established their first winter camp at the Mandan Villages in late fall of 1804, they had an opportunity to check the accuracy of Thompson's coordinates, censuses, and topographical information recorded seven years before.
Soon after the turn of the new year, North West Company trader François-Antoine Larocque arrived at the villages for his company's annual trading session. During his stay, Captain William Clark told Larocque that he disagreed with the longitude Thompson had calculated for the place, explaining he believed that the British surveyor had placed the villages too far to the west. The position of the villages on Clark's 1814 map, although not Thompson's exact reading, is closer to the fur trader's mark than the observations of Lewis and Clark.
When they reached the Rockies in the fall of 1805, Lewis and Clark experienced the same kinds of problems with mountain travel that had impeded David Thompson in the fall of 1800 and the spring of 1801—wider and more separate mountain ranges, wetter and milder weather on the West Slope, a shortage of grass for horses and meat for men. The captains did eventually make their way from the Bitterroot Valley across Lolo Pass to the Lochsa, Clearwater, and Snake drainages, reaching the long-sought Columbia River at what is now Pasco, Washington. They made the initial formal survey of about 200 river miles along the Columbia before they meshed with Lieutenant Broughton's chart at Point Vancouver. From there they continued to the tidewaters and established their winter camp for 1805-06 at Fort Clatsop.
Below the Cascades (1847)
Meriwether Lewis's return across the mountains in 1806 was marked by a skirmish with Blackfeet on the Marias River, very near the 49th parallel. Fur traders at Rocky Mountain House soon heard the Piegan version of the battle, as well as accurate information about the men and movements of the American party as they returned downstream on the Missouri. Tribal people knew that two of the Corps of Discovery turned around at the Yellowstone with the intention of trapping furs, and that numerous parties had already been up the Missouri for the same purpose.
This western movement of trappers is clear in Clark's journal for the lower Missouri section of the Corps of Discovery's journey, and at least two of the men mentioned by Clark—Charles Courtin and François Rivet—would later be named in Thompson's Columbia journals. Other unnamed free trappers, known to both Meriwether Lewis and Thompson as "Illinois River men" after their point of origin, certainly drifted into the Columbia District in the wake of the American Expedition as well.
Canadian free trappers had been crossing the Continental Divide north of the 49th parallel at least since Thompson dispatched his two voyageurs west with a Kootenai band in 1800 and introduced Iroquois trappers onto the east front in 1801. In the late summer of 1806, the Nor'Westers dispatched scouts up the North Fork of the Saskatchewan River to widen one existing Kootenai trail so a trading expedition could embark the following spring. David Thompson arrived back at Rocky Mountain House in October to serve as both lead fur agent and surveyor of the push across the Divide.
Funded in part by a grant from the National Park Service, Challenge Cost Share Program.