II. The Mystery of “La Roche Jaune” or Yellow Rock River
For some twenty years before the advent of Lewis and Clark, French-Canadian voyageurs of the North West Company were in league with the Mandans, and from these Indians learned of the distant “Pierre Jaune” or “Roche Jaune” River, a translation from the Indian equivalent of “Yellow Rock River.” Chittenden theorizes that the ultimate origin of the name descends from the brilliant and infinite varieties of yellow which dominate the color scheme of the Grand Canyon of the Yellowstone, and which probably awed the first aboriginal explorer just as it does today’s auto-borne tourist.
Although there is room for debate as to whether any of the Canadian traders beat Lewis and Clark to the mouth of the Yellowstone, it is certain that one of their number preceded the Americans in the approach to its headwaters. On September 10, 1805, Francois Antoine Larocque reached “Riviere aux Roches Jaunes” just below the mouth of Pryor’s Fork, near present Billings, Montana, in the course of “a voyage of discovery to the Rocky Mountains.” After wintering at the Mandan villages in 1804-1805 as a neighbor of the hibernating Lewis and Clark, and being thwarted in his desire to accompany them upstream, Larocque had returned to his post on the Assiniboine for supplies, then hurried back to the Mandans, going from there overland via Knife River, the Little Missouri, and the Tongue to the Bighorn Mountains, country of the Crows.
While wintering with the Mandans, Captain Clark sketched two maps of the unexplored country westward, based on “the information of traders, indians and my own observation and ideas.” One of these shows “Rochejhone River” with six tributaries from the south, five with Indian names, two translated as “Tongue River” and “Big Horn R.” The Bighorns and Rocky Mountains beyond are represented only by diagrammatic strokes. There is a trail from the mouth of Knife River to the Bighorns, roughly the same subsequently taken by Larocque. This was actually a refinement of a sketch made for Clark by the Mandan Chief Big White. The second map shows “River yellow rock” minus tributaries but with the Crows (“gens de Corbeau”) located just west of an imaginative “montagne de roche—conjecturall.” These maps, the first to our knowledge to depict the Yellowstone River, were sent to President Jefferson on April 7, 1805, by Meriwether Lewis, to accompany his eagerly awaited progress report.
Upon their return trip in 1806, after wintering at Fort Clatsop at the mouth of the Columbia, Lewis and Clark divided in order to explore the country more thoroughly, the latter undertaking to determine the source of the mysterious Yellowstone. On July 15, with eleven white men, the Indian woman Sacajawea and her baby, the cavalcade crossed Bozeman Pass, which marks the divide between the Yellowstone and Gallatin Fork, and reached the vicinity of present Livingston, Montana. Never suspecting what wonders lay concealed behind the snowy mountain wall to the south, Clark hurried on down the river to rejoin Lewis, with glory enough for one expedition.
There is only one hint of volcanic phenomena which Clark seems to have obtained from any source other than the presumed conversation with Colter, mentioned below. This was an Indian tale, received after Clark’s return, but before Colter’s return, to the effect that at the head of Tongue River, a branch of the Yellowstone, “there is frequently heard a loud noise like Thunder, which makes the earth Tremble, they state that they seldom go there because their children Cannot sleep—and Conceive it possessed of spirits, who were averse that men Should be near them.” Speculates Vinton, “it can hardly be doubted that the Indians referred to the geyser basin in the Park,” rather than to the Tongue River neighborhood.
It is commonly supposed that, prior to Colter, no white man had knowledge of strange phenomena on the Upper Yellowstone, this supposition being one of the pillars of the “first-discovery” theory. It is fairly evident that Clark knew nothing of geysers when he was within seventy-five miles of them in 1806 but, ironically enough, at this time some intimation of them had certainly reached others, including Clark’s sponsor, Thomas Jefferson. On October 22, 1805, James Wilkinson, governor of Louisiana Territory, with headquarters in St. Louis, sent to the President, in care of Captain Amos Stoddard,
a Savage delineation on a Buffalo Pelt, of the Missouri & its South Western branches, including the Rivers plate & Lycorne or Pierre jaune; This Rude Sketch without Scale or Compass ‘et remplie de Fantaisies ridicules’ is not destitute of Interests, as it exposes the location of several important Objects, & may point the way to useful enquiry—among other things a little incredible, a volcano is distinctly described on Yellow Stone River.
Wilkinson apparently obtained this primitive map from unidentified traders. It could not have been a copy of Clark’s map sent from Fort Mandan the April previous, for it obviously contained new data. In an advice to Henry Dearborn, Secretary of War, dated September 18, 1805, Wilkinson revealed that his interest in Yellowstone curiosities was sufficiently aroused to dispatch an expedition of his own upriver!
I have equipt a Perogue out of my Small private means, not with any view to Self interest, to ascend the missouri and enter the River Piere jaune, or yellow Stone, called by the natives, Unicorn River, the same by which Capt. Lewis I find since expects to return and which my informants tell me is filled with wonders. This Party will not get back before the Summer 1807—they are natives of this town....