Missouri Headwaters

Clark's Seminar at Fort Mandan

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interactive map showing place names

Map Division, Library of Congress

The map assembled for Lewis and Clark by Nicholas King in 1803, the one that purportedly contained the most accurate information the best cartographers had in 1802-3 concerning the Northwest, showed two forks identified as the "Missesouri" and "Lesser Missesouri" flowing more or less directly eastward out of a single range "Shining Mountains" between the "Boar's Tooth," in the vicinity of Helena, Montana, and Glacier National Park, near the present Canadian border. That is, between the 45th and 50th parallels. It showed most of the dozen or so headwaters as being known within a short distance of the Rocky Mountain Front, but showed them as conjectural from there almost to the Knife River Villages.

By the close of the winter of 1804-05, however, Clark and Lewis had a different picture of where they and the Corps were headed. Collating what they had learned from traders and travelers in the vicinity of St. Louis, and the lessons from their informal seminars with Canadian traders and especially with Indian informants such as Sheheke and Black Cat, Clark concluded that the Missouri River flowed northward first, then eastward. He was led to the conjecture that, in his terms, those sources lay between 40° and 41° North Latitude. (In fact, the source of the Missouri is in the vicinity of 45°04' North.) Clark's estimate was nearly 300 miles too far south, however (one degree of latitude equals approximately 69 miles), and if that wasn't just a simple miscalculation or a rough generalization, it may have reflected an effort to make his map conform to the then-current theory that the Missouri began on a "height of land" near the sources of the Platte and Rio del Norte.

Detail, Clark's map of 1805

hand drawn map of the Three Forks with modern labels

War Department Copy

Still later, in his final map of the Northwest (1814), Clark estimated the sources of all three rivers at about 44° North, not more than a few miles from reality, considering that he never saw any of them. In fact, the Jefferson begins in the Red Rock Lakes area at near 44 degrees 37 minutes 20 seconds north, 111-30-45 W. The Madison—called the Firehole River where it rises in Yellowstone National Park—is at 44°21' North, 110°52' West. The Gallatin begins at 44°51'20" North, 110°53' West. On the same map (1814), he located the confluence of the headwaters at about 45° North and 110° West. At present, the Missouri River "officially" begins at the confluence of the Jefferson and Madison Rivers, which is at 45°55'37" North, 111°30'24" West.1

The astonishing thing is that the two explorers managed to figure out ways of asking questions of their various informants, and of interpreting answers, in concepts that bridged major cultural and intellectual chasms—linguistic, mathematic, geometric, and geographic—to arrive at the mutually agreeable, if temporary, conclusions Clark recorded in his 1805 map.

It was a worrisome time, that ten-day stretch between reloading the canoes above the Falls, and reaching the headwaters of the Missouri at the confluence of the Three Forks. On July 24, Lewis fretted over the possibility they might still "meet with some considerable falls or obstruction in the river notwithstanding the information of the Indian woman to the contrary." He could "scarcely form an idea of a river runing to great extent through such a rough mountainous country without having it's stream intersepted by some difficult and gangerous [dangerous] rappids or falls."

Since passing Dearborn's River on July 18, Lewis had had complete command over the six dugout canoes, proceeding by means of the cord and setting poles—"the oars scarcely ever being used except to pass the river in order to take advantage of the shore and current"—while Clark and a small detail of men hurried ahead, overland. All were "anxious . . . to meet with the Sosonees or snake Indians as soon as possible in order to obtain information relative to the geography of the country." Their hope was for the advance party to make the first contact with them lest the natives be frightened away by the sounds of the hunters' guns. Clark and his detail paid a great price in sore feet because of the sharp, flinty rock they walked on while tracing their route through and around the "Gates of the Mountains." It was a wide Indian road that appeared to have been dug out of the mountainsides in many places. Perhaps Clark and his men were following a branch of the historic Old North Trail that followed the fringes of the Rocky Mountain Front.

Thursday, July 25, dawned on "a fine morning." Clark, with Frazer, the Field brothers, and Charbonneau,

proceeded on a fiew miles to the three forks of the Missouri those three forks are nearly of a size, the North fork appears to have the most water and must be Considered as the one best calculated for us to assend. The South fork is about 70 yds wide & falls in about 500 yards below the midle fork. those forks appear to be verry2 rapid & Contain Some timber in their bottoms which is verry extincive.

Scarcely pausing, and even though wracked with chills, high fever, and "constant aking pains in all his mustles"—perhaps symptoms of the first recorded case of Colorado tick fever3—Clark proceeded on in search of Shoshones. He went up the Jefferson a ways, climbed to the top of a mountain "with great dificuelty & much fatigue" to gain a view of the valleys and mountains ahead, then turned east as far as the Madison River, and followed it back to the rendezvous point. Meanwhile, he left a note for Lewis at the confluence of the "S. W. and Middle forks,"

informing [Lewis] of his intended rout, and that he would rejoin me at this place provided he did not fall in with any fresh sighn of Indians, in which case he intended to pursue untill he over took them calculating on my taking the S. W. for, which I most certainly prefer as it's direction is much more promising than any other.

Lewis and his canoes slowly approached the forks, "the current still so rapid that the men are in a continual state of their utmost exertion to get on, and they begin to weaken fast from this continual state of violent exertion." He explored and described the "extensive and beatifull plains and meadows." He halted the party for breakfeast, and himself "walked up the S. E. fork [the Gallatin] about 1/2 a mile and ascended the point of a high limestone clift from whence I commanded amost perfect view of the neighbouring country." From that point he could look up the Gallatin valley about 7 miles, which suggests he may have climbed some 250 feet to the top of "Lewis's Overlook."

Believing this to be "an essential point in the geography of this western part of the Continent," Lewis determined to remain long enough to record the necessary data for fixing its latitude and longitude. He took note of the surrounding mountain ranges, as well as "a handsom site for a fortification," consisting of "a limestone rock of an oblong form; its sizes perpendicular and about 25 ft high except at the extremity towards the middle fork where it ascends agradually and like to top is covered with a fine terf of greenswoard. the top is level and contains about 2 Acres. the rock [r]ises from the level plain as if it had been designed for some such purpose."

The next morning, the 28th, Lewis dispatched two men up the S. E. Fork to examine the river, and then he and Clark summarized their conclusions:

Both Capt. C. and myself corrisponded in opinion with rispect to the impropriety of calling either of these streams the Missouri and accordingly agreed to name them after the President of the United States and the Secretairies of the Treasury and state having previously named one river in honour of the Secretaries of War (Dearborn's River) and Navy (Smith's River). In pursuance of this resolution we called the S. W. fork, that which we meant to ascend, Jefferson's River in honor of that illustrious personage Thomas Jefferson. [Nicholas Biddle?: the author of our enterprise.] the Middle fork we called Madison's River in honor of James Madison, and the S. E. Fork we called Gallitin's River in honor of Albert Gallatin. the two first are 90 yards wide and the last is 70 yards. all of the run with great valocity and throw out large bodies of water. Gallitin's River is reather more rapid than either of the others, is not quite as deep but from all appearances may be navigated to a considerable distance. Capt. C. who came down madison's river yesterday and has also seen Jefferson's some distance thinks Madison's reather the most rapid, but is not as much so by any means as Gallatin's. the beds of all these streams are formed of smooth pebble and gravel, and their waters perfectly transparent; in short they are three noble streams.

there is timber enough here to support an establishment4, provided it be erected with brick or stone either of which would be much cheaper than wood as all the materials for such a work are immediately at the spot. there are several small sand-bars along along the shores at no great distance of very pure sand and the earth appears as if it would make good brick. . . .

I observe large quantities of the sand rush in these bottoms which grow in many places as high a man's breast and stand as thick as the stalks of wheat usually do. this affords one of the best winter pastures on earth for horses or cows, and of course will be much in favour of an establishment should it ever be thought necessary to fix one at this place. the grass is also luxouriant and would afford a fine swarth of hay at this time in parsels of ma[n]ly acres together.

Our present camp is precisely on the spot that the Snake Indians were encamped at the time the Minnetares of the Knife R. first came in sight of them five years since. from hence they retreated about three miles up Jeffersons river and concealed themselves in the woods, the Minnetares pursued, attacked them, killed 4 men 4 women and a number of boys, and mad presoners of all the females and four boys. Sah-cah-gar-we-ah o[u]r Indian woman was one of the female prisoners taken at that time; tho' I cannot discover that she shews any immotion of sorrow in recollecting this event, or of joy in being again restored to her native country; if she had enough to eat and a few trinkets to wear I beleive she would be perfectly content anywhere.—

The following day. Monday, the men were "busily engaged all day in dising [dressing?] skins and making them into various garments[;] all are leather dressers and taylors." Meanwhile, exploration and observation of all things, great and small, continued at the usual pace: "There is also in these plains a large ant with a redish brown body and legs, and a black head and abdomen; they construct little perimids of small gravel in a conic shape, about 10 or 12 inches high without a mixture of sticks and with but little earth." Judging from Lewis's description, it was perhaps the Western harvester ant.

On the 30th the entire party set out up the Jefferson's River, with Clark again in command of the canoes. It was an arduous day for the men, who made good time—an estimated 12.5 miles—despite having to make 29 changes of course. Lewis proceeded overland, alone.

The Three Forks, 2006

View south from above the confluence

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Interactive aerial photo showing place names

© 2001 Airphoto, Jim Wark. All rights reserved.

Parallel lines of latitude and longitude, made visible by the roads and highways that trace them, impose the basic design of the Rectangular Survey System upon the random sinuous patterns of watercourses and a few hills. Modern high-speed highways such as U.S. 287—begun in 1939 and completed in 1965, connecting Port Arthur, Texas, with Choteau, Montana—are routed and graded for optimum efficiency, without regard for the constraints inherent in the Rectangular Survey System.

Essential Infrastructure of the West

So certain did it seem in 1867 that this was destined to be the heart of Montana Territory, that the location of an "Initial Point" for the required rectangular land survey grid was officially established by the Territorial Legislature in that year. The first choice was the highest point on Beaverhead Rock, but it appeared that agricultural settlement was going to begin farther north, in the Gallatin valley near the Three Forks of the Missouri. For that reason the Initial Point—the intersection of a designated "Principal Meridian" with a designated "Base Line—was officially established about one mile west and three miles south of the town of Willow Creek, on the summit of a foothill rising some 500 feet above the nearby mouth of Willow Creek.5 Specifically, that elevation was determined to lie at 45°47'13" North Latitude, and 111°39'33" West Longitude.

That particular point was chosen was because agricultural settlement was quickly expanding into the rich Gallatin valley, and farmers needed to establish their claims by legal, professional surveys. (Of course, a few unprincipled settlers merely squatted on some prime land and declared they were occupying mining claims.) The location of the Principal Meridian was important because of clear visibility from there, and the ease with which survey lines could be extended in all directions.

Beginning at the Initial Point in 1867, surveyors carefully calculated latitudes and longitudes by celestial observations and intricate formulas in spherical trigonometry, and proceeded to mark off six-mile squares called Townships in the valley. Each Township was divided into thirty-six square-mile Sections. The four corners of each section were marked by permanent "monuments"—originally of native stone with the description of the corner chiseled into them. Each section was divided into four 160-acre quarter-sections. Each acre contains 4,850 square yards or 43,560 square feet.6

The purpose of the Rectangular Survey System, which had been initiated by the Continental Congress at Thomas Jefferson's instigation in 1785, was to facilitate the transfer of land from government to individual ownership in a more orderly way than was possible under the ancient "metes-and-bounds"—literally, "points and lines"—system, in which land ownership was based on irregularly-shaped plots defined by arbitrarily selected natural features.7 There was resistance to Jefferson's Land Ordinance on the part of prospective landowners because through the older principle a speculator or landowner could place the best land in a given area within an irregularly shaped boundary, and to Hell with the hindmost. Before the Initial Point was established in Montana, some of the largest cattle ranches had already been claimed by merely staking out generally desirable limits—and grandly expansive—dimensions, and thereupon declaring "right of possession." The rectangular system was more equitable, both for fair distribution of land ownership and for taxation purposes.

1. The length of a degree of longitude at latitude 45°N is almost exactly 49 statute miles; a degree of latitude between 44°30' and 45°30' North is 69.05 statute miles.

2. The journalists, especially Clark, spelled this ordinary and typically overused adverb with 2 rs about half the time. That was one of the old spellings of the word, to be sure; Lewis, with the better education, most often used just one r. But also the double-r spelling may have invoked a common inflection or phonetic convention that emphasized a shade of meaning synonymous with "extremely," as in "verry foggy this morning" (Lewis) or, in this instance, a verry rapid stream. That "verry fine morning" soon deteriorated into a "verry" hot day. It may also have been a local or regional convention, like the monosyllable "few" sounded like a two-syllable word when uttered by a rural Kentuckian such as Clark—"fiew" (fee-oo). Later on the same day, July 25, Clark climbed a mountain with great "dificuelty." Pronounce that slowly, exactly as spelled, and speed it up until it feels natural, and see if it isn't a perfectly logical spelling for the sound of an adult rural Kentuckian who has some "dificuelty" with spelling.

3. See Ronald V. Loge, "Illness at Three Forks: Captain Clark and the First Recorded Case of Colorado Tick Fever," Montana: The Magazine of Western History, Vol.. 50, No. 2 (Summer 2000), 2-15.

4. Clark's list of prospective trading posts (Moulton, Journals, 3:479-80) did not include one at the Three Forks of the Missouri. Pierre Ménard and Andrew Henry of the Missouri Fur Company built a post there in 1810, but the Blackfeet soon drove them out.

5. When settlement began in the valleys south of the Three Forks in 1864 amid the distractions of a nearby gold rush, no one thought to consult Clark's 1814 map to see if the captains had already given it a name. They had. On July 25, 1805, they named it Philosophy River, in observance of one of the virtues upheld by the fellowship of Freemasonry, soon adding the Philanthropy River (now the Ruby), and the Wisdom (Big Hole). The sources of the Philosophy River/Willow Creek are high on the west slopes of the Tobacco Root Mountains.

6. The entire State of Montana has never been completely divided into Townships, Ranges and Sections by on-the-ground surveys. Instead, the U.S. Bureau of Land Management has "protracted" the survey lines into the un-surveyed areas by cartographic techniques.

7. Jefferson's Act was modeled on British surveys of India in the mid-18th century, which comprised an elaborate census of all aspects of geography in order to more efficiently extend control over the colony. The six-mile-square British section was based on the French 10-kilometer military grid; 10 km = 6.25 miles.