The white pirogue, smaller but more stable than the red, was the queen of the little fleet. In her lockers the captains stored their astronomical instruments, several casks of gunpowder, medicines, their best trade goods, their journals, and other valuable papers. For safety's sake, the three privates of the expedition who could not swim were assigned as oarsmen to this "flagship." (The boat's full complement of rowers was six.) Also riding in the white pirogue were Sacagawea and her two-month-old baby, her husband, Toussaint Charbonneau, the hunter-interpreter George Drouillard, and captains Meriwether Lewis and William Clark. 
The close association continued at night, when the captains sought shelter with Drouillard, Charbonneau, and his family in a movable leather tepee. It was made of several expertly tanned buffalo hides sewed together in such fashion that they formed a tall cone when draped around a dozen ten-foot-long lodge poles.  Presumably the poles were also carried in the boat, for suitable slim, straight timbers were not always easy to find along the river's edge.
Generally speaking, Indian women set up their families' lodges after each move, but it would have been unduly time-consuming for Sacagawea to have struggled alone with the awkward tent each morning and evening. Since it is difficult to imagine Charbonneau losing face, in his own estimation, by lending her a hand, conjecture veers to York. The black slave (Clark always referred to him as "my servant") was enormously strong, fat, amiable, and trained by long experience in the ways of wilderness housekeeping. Probably York and Sacagawea also cooked for the occupants of the tepee. Charbonneau, who was an expert at making boudins, a sausage encased in somewhat cleansed buffalo intestines, may have helped prepare other dishes as well.
During the first week of travel, the expedition traversed the crinkled, miles-long curve called the Great Bend of the Missouri. There the Mississippi-bound river gave up its eastern course and struck south. For the boatmen, passing the Great Bend meant they were at last heading due west toward the setting sun, the Pacific. Spirits were high, and the spring weather smiled in accord. Gray disintegrating heaps of ice, pushed onto the banks and sandbars during the breakup, were the only remaining signs of winter. The trees in the bottomlands were beginning to bud; flowers spangled the greening plains, where flocks of geese fed on the new grass. Their square sails raised whenever the winds favored, the two pirogues and the six cranky new dugouts covered the ninety-three miles to the mouth of the Little Missouri in slightly more than four days. 
Paradise did have flaws. Riverside bluffs were occasionally obscured by mephitic smoke rising from seams of lignite coal set to smoldering years before either by spontaneous combustion or by grass fires—the source, probably, of tales told by French-Canadians of volcanoes in the mysterious West. (Years later, the surveyor Ferdinand Hayden declared, "The sulphurous smell which issues from these fires is exceedingly offensive.") Other disagreeable odors rose from scattered piles of decaying buffalo carcasses; the animals had drowned when the spring-softened ice gave way under them, and afterwards had been deposited on exposed shores by the high water of spring. A more familiar discomfort appeared on April 9, the year's first "musquetor." By the next day the pests were troublesome, and would stay that way for months to come.
Food was limited, at first, to parched corn and jerky. The men craved fresh meat, but Hidatsa and Assiniboin hunters had frightened the game out of the river valley within two or three days' ride of the villages. The animals the Corps finally did see were too winter-lean to be acceptable, except for their tongues. Another substitute was the flesh of the beaver they shot or trapped; a single long, flat tail provided, when broiled, a feast for two hungry persons. They killed geese now and then, and also helped themselves to the eggs in whatever nests they found. To their surprise, most of the goose nests they spotted were high in lofty cottonwood trees. Sacagawea showed them how to find caches of unfamiliar but edible roots that gophers stored near piles of driftwood. Meanwhile, buffalo calves were growing and were fat, even if their mothers weren't. So buffalo veal became, for a time, a mainstay of the thirty-two adult travelers and of Lewis's big, black Newfoundland dog.
As the days passed, the violence of the north and northwest winds increased. Sudden squalls added to the problem. Early in the afternoon of April 13, while Toussaint Charbonneau was at the tiller of the white pirogue and the boat was bounding easily over high, opaque waves where the river was several hundred yards wide, an unexpected gust lashed obliquely across the water. The boat listed dangerously. Charbonneau froze. Lewis yelled for Drouillard to take the tiller and for the other crew members to drop the sails. The boat staggered upright, undamaged. "This accedent," Lewis admitted in his journal, "was very near costing us dear." But he did not shift any of the pirogue's valuable cargo to other boats or make any changes in the crew's assignments.
Perhaps he thought there would be no use in doing so. The six long, narrow dugouts, invariably called "canoes" in the journals, were particularly vulnerable to the unremitting force of the wind. This was especially true when the fleet had to turn some long, exposed point. Slapped hard by the waves, the unstable craft and, more than once, the pirogues shipped water. If the wetting was serious, the cargo had to be unloaded and spread out to dry.
Sometimes the travelers could buck adverse winds by breaking out the tow ropes and dragging the craft ahead. At other times, perhaps for a few hours and on occasions for an entire day, they could not move at all. At such times they tried to find a cove where they could tie the dugouts to the shore and anchor the pirogues in front of them as breakwaters. The gales blew sand off the bars in streamers like smoke. "We are compelled to eat, drink, and breath it very freely," Lewis wrote, to which Clark added, "The party complain much of the Sand in their eyes." In time the inflammations grew serious enough that Lewis dug into the medicine chest and concocted an eyewash of white vitriol and sugar of lead (zinc sulphate and lead acetate). Meanwhile Clark fretted that "the winds of this country . . . have become a serious obstruction to our progress onward." 
Wind or not, the captains never forgot that one of their main assignments was to learn what they could of the land and its wildlife. Lewis was the one who spent the most time afoot on this assignment. Head bent against the gales, he wandered along the broad trails the buffalo had trampled into the earth and noted admiringly the exactness with which the shaggy beasts had worked out the most efficient routes from one point to another. He climbed the bluffs on both sides of the river to learn how plants, birds, and animals had adapted to the varied environments. He detected the difference in the habitats preferred by mule deer and white-tailed deer. He marveled at the way wolves would cut one antelope out of a herd and then spell each other as they ran the fleet-footed prey to exhaustion. He listened intently to bird calls so that he could render the sounds phonetically on paper. When he came across unfamiliar plants he tested them with his tongue, nose, and fingertips in order to be able to convey the most accurate description possible—descriptions often hundreds of words long and composed by the dwindling light of the evening's campfire. Unfortunately he never published a scientific paper on his findings and so later naturalists, acting in full honesty, often received credit for bringing to the world's attention bits of lore that Meriwether Lewis had first portrayed. 
Clark contributed fully. Sometimes he left spare accounts of things he had seen. More often he told Lewis about the discoveries he had made during one of his own strenuous hikes and let his friend handle the paperwork. Clark's main job was cartography. As he had done on the way up the Missouri to the Mandan villages, he kept careful compass records of the river's many turnings and of mileages between prominent points, as computed by dead reckoning. He then transferred the data onto separate sheets of paper, as he had done the previous year. Limited though the strip maps were to the river's immediate environs, they nevertheless could be used to check, in part, the accuracy of the big, conjectural map of the West he had drawn at Fort Mandan during the winter, relying mainly on information collected from the Indians and then transferred to the basic King-Arrowsmith map they were carrying with them. 
Results excited the captains. The Little Missouri came in from the south and the White Earth River from the north, as the Indians had said they would. The Indians had also said, or so the captains had understood, that the White Earth was navigable almost as far north as Canada's South Saskatchewan River, as portrayed on their King-Arrowsmith chart. If so, the White Earth could be used for tapping the great fur country of the Canadian Northwest. Buoyed by that hope, they walked beside the tributary for about four miles. It should not have struck them as prepossessing. Its low, steep banks were stained white with patches of alkali; its bed, Lewis wrote, "seems composed of mud altogether." Swollen by spring runoff, it was about sixty yards wide. Later settlers, seeing the stream at a drier season, would name it Little Muddy Creek. But Lewis and Clark wanted it as a highway for American commerce, and they wrote about it with the ink of hope, a strange aberration for two normally competent observers. 
Three or four miles above the mouth of the White Earth, another tributary of special interest to Lewis and Clark entered the Missouri. This one came from the south and was truly majestic. The Hidatsas called it Mee, Ah-zhah. As noted earlier, it was not unknown to white men. French-Canadian voyageurs and traders of the original Missouri Fur Company had been calling it Roche Jaune for more than a decade. Roche Jaune, the River of Yellow Rock, or Yellowstone. The name is inexplicable, for there is no indication that any of the whites who wrote about it had yet heard of, let alone seen, the vivid yellow walls of the river's upper canyon. Nevertheless, the stream, labeled Yellowstone through some strange coincidence, appears strongly on Clark's conjectural map, where it reaches much too far south across lands barely rippled by mountains.
Such a stream merited actual examination, not guesswork. During their winter with the Mandans, the captains had laid plans to explore it on their return journey to the States. Before then, however, they wanted to determine the geographic coordinates of its mouth for the sake of Clark's strip maps. When contrary winds pinned the fleet against the banks of the Missouri, Lewis decided to speed matters by going ahead on foot, accompanied by Drouillard, Ordway, and the brothers Joseph and Reuben Field. After taking his readings, he would wait for the boats to follow when they could.
The quartet climbed to the top of the Missouri's southern bluffs and struck overland toward what they assumed would be the junction—if Indian descriptions were correct. Elation filled them. There it was, strong and beautiful, curling lazily through a wide, fertile plain streaked with magnificent stands of trees, their new leaves glistening in the sunlight. Then and there Lewis decided, with the sense of wonder that is one of his most appealing characteristics, to camp on the Yellowstone's banks, amid vast herds of wildlife, and enjoy the pristine scene before taking his observations.
The next day Joseph Field explored the river upstream as far as he could walk and return before dark. Meanwhile the others roamed the area around the junction, thinking, inaccurately, that no other white men had seen this unspoiled Eden.  They picked out a site where a United States government trading post might be located in competition to the British, if the newly amalgamated Hudson's Bay and North West companies sought to take over the fur business of this lovely section of Louisiana Territory. (Though no government post was ever built at the junction, a series of commercial ones eventually were.)
They could not get over the amounts of wildlife. "The whole country was covered with herds of buffaloe, Elk & Antelopes ... so gentle we pass near them without appearing to excite any alarm, and when we attract their attention they approach more nearly to see what we are." Lewis was so exhilarated that when the quartet rejoined the boats close to the confluence that evening, he ordered "a dram to each person; this soon produced the fiddle, and they spent the evening with much hilarity, singing and dancing, and seemed perfectly to forget their past toils, as they appeared regardless of those yet to come." 
Did Lewis and Clark ever sing and dance during lighthearted moments? The journals never mention such levity, and probably the captains' sense of what was fitting—that inevitable gap between officers and enlisted men—held them back. But surely their hearts sang. To be here, to open for their countrymen such a gate as this! And they still had close to two thousand miles to go. What more remained for them to find!
On they labored, the river making S-curves ahead of them like a slow-traveling bullsnake. Past thick strata of coal, some of it burned dark red by old fires. Into a spell of frigid weather: ice on the water buckets, a dervish dance of snowflakes that whitened the ground and led Clark to exclaim that it was a "verry extraordenarey climate, to behold trees Green & flowers spred on the plain & Snow an inch deep."  But it was a fine country for all of that. The broad bottomlands were filled with more timber than the explorers had seen since passing the hundredth meridian. And the game was fattening—ducks, swans, buffalo, antelope, elk, beaver. "It is now only amusement," Lewis said, "for Capt. C and myself to kill as much meat as the party can consum." But except for grizzly bears they killed no more than they needed, and they restrained the men as well. Their superiors in Washington would read such remarks with interest, for any army detachment ordered to penetrate the West would have to live off the land. 
On May 8 they reached, sooner than they had expected, a large tributary flowing into the Missouri from the north. Since the Indians had said there was only one such stream beyond the White Earth River (or so the captains had understood), this must be it. Not liking the Indian name, which translated as "The River That Scolds at All Others," they rechristened it Milk because it was "about the colour of a cup of tea with the admixture of a tablespoonful of milk." The persistence of hope: if the White Earth did not "furnish a predictable and advantageous communication with the Saskashiwan river," this one might.
On and on, into adventures the captains, to whom safety was a prime requisite, probably would have been glad to skip—their feud with grizzly bears and, simultaneously, additional mishaps with the white pirogue.
Bears! The trader Jean Vallé, whom the Corps of Discovery had met far downstream, below the Arikaras, had spoken of the huge beasts with almost tremulous awe. The Mandans and Hidatsas were frankly terrified. Before hunting a grizzly, the Indians painted their bodies as if they were going to war. If a kill resulted, they cherished the creature's curved black talons, each more than four inches long, as fully as they did an enemy's scalp.
Lewis was supercilious about the tales. After all, the natives had nothing better to hunt with than bows, arrows, and notoriously wretched trade muskets. A skilled white, equipped with one of the new Harpers Ferry rifles, should have no trouble. The fact that the bears were carrion eaters, leaving their huge tracks in profusion around the heaps of drowned, decaying buffalo corpses, may have added to his scorn without his being aware of it.
His first encounter did little to change his mind. While walking along the shore early in the morning of April 29, a companion and he ran across "two brown or yellow bears." (At first the explorers called the bears white, as their informants had. A strange error. The massive beasts are not white. However, the tips of their yellowish reddish, or even almost black hair are lighter than the basic strands, so that in certain lights they do appear grizzled. Lewis later spoke of "grisly bears," Clark of "Grisley bears." Grizzly ... or perhaps "grisly," in the sense of "terrifying, ghastly"?)  The two hunters each picked a target that April morning and each accurately fired the single ball in his rifle. One bear fled. The other performed as the Indians had predicted; it charged. It was hurt, however, and the hunters were able to reload and bring it down. It was half-grown, a mere three hundred pounds, Lewis estimated. He admitted that it had been much more "furious" than an ordinary black or brown bear would have been, but he still believed that grizzlies "are by no means as formidable or dangerous as they have been represented."
A week later, Clark and Drouillard spotted a full-grown one, "turrible looking," standing in the water. Probably it was fishing; the stroke of a grizzly's front paw is lightning fast. Taking careful aim, each man fired, reloaded, fired again for a total of ten shots. Perhaps because the animal did not sense from which direction the attack was coming, it did not charge but swam with a tremendous roaring half the distance across the river to a sandbar. There it died. Some of the party dragged the body back with a boat. It measured eight feet seven and a half inches from the tip of its nose to the extremity of its hind feet. Clark thought it might weigh five hundred pounds; Lewis, six hundred. An autopsy showed that five balls had gone through its lungs; five more had lodged in other parts of its body. Its heart was as large as that of a large ox; its maw, ten times the size of an ordinary black bear's, was filled with flesh and fish. Its fat, rendered out for future use in cooking, as was that of most bears killed later on, yielded a small cask of oil.
The experience, Lewis said, left half the party content to live and let live. "Others however seem keen for action." One of the unconverted was William Bratton. He was suffering with boils—that scourge had broken out again—and was given permission to seek relief by turning his oar over to someone else and walking along the shore. Late in the afternoon he "came running up to the boats with loud cries and every symptom of terror and distress." While alone, he had shot a grizzly dead center, whereupon the enraged beast had pursued him half a mile, but, slowed by its wound, had not quite overtaken him.
No bear could get away with that. Lewis and seven men tracked the animal by its blood and found it had dug itself a kind of nest two feet deep, into which it had curled. They poured a volley into it. By the time it had expired, Lewis was converted. "I . . . had rather fight two Indians than one bear." A figure of speech: he had never fought an Indian. But he had seen grizzlies die, and their fierce farewell to life, he confessed, "intimidated" him.
Nor was that the end of the Corps's education in the ways of bears. On May 14, the six men oaring the two rear dugouts spotted a grizzly snoozing in an open spot and decided to bag it. They crept up behind a little mound until they were within forty paces. Four fired; two held off, in case of emergency. The bear charged and two more shots banged out. One bullet broke the animal's shoulder but scarcely slowed it. The terrified men scattered, hunting cover where they could reload. This did not mean just levering another shell into the firing chamber. As National Park Ranger Dan Murphy, who knows muzzleloaders, has put it, "Get out powder, measure, and pour into barrel. Get out greased patch and ball, put patch on barrel. Put ball on top of it. Draw rammer, ram ball home. Return rammer. Open frizzen. Get out powder again, pour small amount into frizzen pan. Close frizzen. Fire. Repeat." 
Each shot seemed simply to direct the bear toward the shooter. Two men, hotly pursued, flung guns and shot pouches aside, and jumped over a twenty-foot bank into the river. The bear jumped after them and was about to close on one when a man on top of the bluff shot the grizzly (grisly?) and killed it. Thoroughly subdued, the sextet made their way to camp and there found that their act had been topped, unbelievable though it seems, by another of Toussaint Charbonneau's misadventures with the white pirogue.
Both Lewis and Clark had gone ashore that afternoon, leaving the boat and its irreplaceable cargo in charge of Pierre Cruzatte. A shift in the wind was favorable; up went the sails. Distracted by something, Cruzatte turned the helm over to Charbonneau. History repeated. A squall jerked the brace of the square sail out of the hands of the man attending it. Charbonneau lost his grip on the tiller. The boat rolled onto its side and would have turned full turtle if its motion had not been checked by an awning that had been erected earlier to shield the boatmen from the sun. While Charbonneau was "crying aloud to his god for mercy," Lewis, watching aghast from the shore, tore off his coat before realizing he would almost surely drown if he tried to swim to the rescue through three hundred yards of high waves.
Brandishing his rifle and howling like the squall itself, Cruzatte brought Charbonneau to his senses. The men in the boat threw their weight against the high tide. The pirogue ponderously righted, filled with water to within an inch of its gunwales. Bailing and rowing frantically, the crew got it ashore. All this while Sacagawea, sitting up to her waist in water and presumably holding her child in one arm, reached out and with "fortitude and resolution caught and preserved most of the light articles which were washed overboard" (Lewis's words). 
Two narrow escapes in a single day. The bear might well have killed one or more men. The loss of the white pirogue could have ended the expedition altogether. As the soldiers put up a makeshift camp before spreading the baggage out to dry, the captains decided "to console ourselves and cheer the sperits of our men and accordingly took a drink of grog and gave each man a gill." As a more permanent memento they named the little side creek near the site "Brown Bear Defeated Creek."
They spent two increasingly precious days drying out the pirogue's cargo. The main losses turned out to be a disturbing amount of medicine, some gunpowder, and several cooking utensils. On the 17th they took off again, hauling the boats against the wind by tow lines. As usual, they went to bed that night without extinguishing their campfires. Long after those in the leather tepee had fallen asleep, the guard roused them. A big dead tree had caught fire and was about to topple onto the lodge. Hastily its occupants moved the tepee about fifty yards away, whereupon the tree crashed. "A few minutes later we should have been crushed to attoms" (Lewis). But they had not escaped entirely. Wind-dashed sparks severely damaged the leather lodge and set piles of driftwood afire, which "much harassed" the party and resulted in naming the nearby side stream, on Clark's strip map, "Burnt Lodge Creek."
One more naming. May 29. All but the sentry were asleep. A huge buffalo bull swam across the river, bumped into the white pirogue, and heaved itself over the stern. From there the heavy-shouldered beast charged into the camp, its big hooves thundering within inches of some of the sleeping men. Alarmed by the yells of the sentry, the bull swerved directly toward the hard-used tepee. The dog Seaman's furious barking drove it aside and shortly the pandemonium subsided. At daylight the Corps discovered that the bull had broken, during its climb across the pirogue, the stock of one of the swivel guns, part of the rudder's mechanism, and York's rifle. "it appears," Lewis wrote, "that the white perogue, which contains our most valuable stores is attended by some evil gennii." The closest creek was named "Bull Creek."
And a postscript. May 30. Not long after leaving Bull Creek, the fleet passed the mangled, horribly odorous remnants of at least a hundred buffalo that the men decided had recently been stampeded over the cliffs above by Indians. Lewis expatiated on the procedure. A fleet-footed decoy disguised in a buffalo hide placed himself between a herd and "a precipice proper for the purpose"—a phrase to remember. Other Indians who had quietly surrounded the herd on all but the cliff side suddenly leaped upright and frightened the animals into flight. The decoy guided them to the brink of the precipice, then stepped nimbly aside and over the animals went, a waterfall of flesh.
Though buffalo pishkins (a Blackfoot word) certainly occurred, modern archeologists who have clambered about the site described by Lewis and mapped by Clark doubt that those particular precipices were "proper for the purpose." They can be approached only across a long span of steep, ragged ground not conducive to a headlong stampede. According to the doubters, the putrid heap on the bank was composed of animals that had perished by falling through the spring-weakened ice and had later been deposited by high water, as had other collections of dead buffalo the Corps had noticed farther downstream. Maybe so. But at least one documented killing took place there, among the enormous number of overfed wolves that had collected around the corpses. They paid so little attention to Clark as he walked among them that he was able to step up beside one and, as an experiment, thrust his espontoon (more generally spelled "spontoon," which is a short pike equipped with a steel point) through its rib cage into its heart. With these many items in mind, the captains named the next stream they came to "Slaughter Creek," a designation settlers later changed to Arrow Creek. 
During the latter part of this month of namings, the land grew markedly more arid. The sides of the river trench were more broken, and the Missouri itself, murderous with sawyers, grew still more crooked. Most side channels were either dry or contained trickles of water so impregnated with alkali as to be scarcely potable. Springs of the sort common in the eastern United States were rare, and dews almost never occurred. A snow flurry early in May and a shower on May 18 were the only precipitation the Corps encountered during seven weeks after leaving the Mandan towns.
Except for a few scraggly pines and patches of low, ground-hugging juniper that appeared near the tops of the steep bluffs north of the river, the principal growth on the hillsides consisted of different varieties of sagebrush, saltbush, and prickly pear cactus, all of them typical of arid lands. A useless country, Clark implied: "[It] may with propriety I think be termed the Deserts of America for I do not think it can ever be settled." Even that persistent romantic, Meriwether Lewis, spoke of "a desert, barren country," and rejoiced in the cottonwoods of the bottomlands, whose "appearances were quite reviving after the drairy country through which we have been passing." 
The Musselshell River, whose mouth they visited on May 20, aroused no particular comment. The name came via translation from the Indians, who long before had noticed the huge number of fossilized mollusc shells in the vicinity. The circumstance suggested an ancient inland sea, as that amateur paleontologist, Thomas Jefferson, and some of his friends in the American Philosophical Society might have realized. But Lewis and Clark, pressed for time, did not pause to look for fossils.
What really interested them right then were the distant, isolated ranges of high, snow-streaked mountains that rose out of the plains both north and south of the river. A puzzle. According to the captains' calculations, based on their well-worn King-Arrowsmith map as amended according to Indian information, they were still far from the Rocky Mountains. The Indians, moreover, had not mentioned these islands in the sky, or at least neither Lewis nor Clark had picked up any such statements. In an effort to explain the solitary massifs, the captains decided the mysterious peaks had to be a northward extension of the Black Hills, whose length they had already greatly exaggerated. This new conjecture was also wrong, but it was comforting, for it put an otherwise inexplicable phenomenon into context. 
Another surprise (for it, too, had not been mentioned during the winter's interviews with the Hidatsas) was a clear, handsome stream that entered the Missouri about two and a half miles above Slaughter Creek. After hiking up it for several miles, Clark "thought proper to call it Judieth's River," after Julia (Judy) Hancock. Julia was then a child of thirteen and one hesitates to think that Clark was already contemplating marrying her, as he did when she was sixteen, or that Lewis supposed he would. Nevertheless this gesture toward the fair sex, the first of its kind among scores of namings, impressed Lewis romantic bent, as we shall shortly see.
By the latter part of May the Corps was traversing, with infinite labor, a wildly beautiful stretch of the river known today as the Breaks of the Missouri and still a fantasyland in spite of being partially mutilated by the huge Fort Peck Reservoir. In a section the explorers called the Stone Walls, the multihued bluffs were banded with a thick stratum of almost horizontal white sandstone. In places this band was seamed perpendicularly by intrusive dikes of dark brown volcanic porphyry. Erosion of the softer material around the dikes had left the jointed rock standing as trim as walls, only a few feet thick and often scores of feet tall, of "workmanship so perfect . . . that I should have thought that Nature had attempted to rival the human art of masonry" (Lewis). Elsewhere water draining off the land back of the steep bluffs had worn the white sandstone "into a thousand grotesque figures . . . collumns of various sculptures both grooved and plain . . . some collumns standing and almost entire with their pedestels and capitals . . . some lying prostrate and broken." Pyramids, organ pipes, spires, niches, alcoves—scores of scenes of "visionary inchantment."
Fittingly enough, this entrancing region was inhabited by large numbers of Rocky Mountainbighorn sheep. As early as April 29, some members of the Corps had glimpsed a few of the creatures skipping gracefully over rocky hillsides that looked too precipitous for any hoofed animal to cross. At that time the explorers had been unable to obtain specimens. In the Breaks, however, the sheep became common, and on May 25 three members of the party shot three animals. Lewis described them and their massive, circular, laminated horns in admirable, even practical detail: "I have no doubt of [the horns'] elegance and usefullness in hair combs, and [they] might probably answer as maney valuable purposes to civilized man, as [they do] to the native Indians, who form their water cups, spoons, and platters of it," as well as fancy, transparent, and elastic bows. The animals were perhaps too lovely for their own good; the Audubon subspecies of the bighorn, which was the one Lewis described, became much sought after by hunters and is now extinct. 
The Corps worked their way past these visionary enchantments at heavy physical cost. Although the Missouri was about as wide as ever, it had grown shallower and swifter. Near the mouths of side streams were jumbles of rocks that had been washed into the main river by occasional flash floods. The only way to surmount the dancing rapids that resulted—and also to buck the wind with its flying clouds of powdery sand—was to tow the boats. Sometimes the men struggled ahead in icy water up to their chests. Sometimes they hobbled, in their homemade leather moccasins, through cactus and over sharp stones fallen from the cliffs. The year's first sustained rain, which fell on May 29 and 30, made matters worse by turning the clay soil into a slippery goo so tenacious they had to fight their way ahead on bare feet.
If an elk-hide rope stretched out and broke in the swift water, the boat involved was apt to swing sideways to the current and drift downstream. If it then struck a rock, it was likely to overturn unless salvaged first by the nimble work of the pursuing boatmen. In bad places, accordingly, the human draft horses observed great caution. In spite of that, the only hemp rope in the outfit, and the one reserved for the white pirogue, snapped. Heeling around, the craft barely touched a boulder and almost upset before crewmen could leap aboard and put it to rights. Lewis was disgusted: "I fear her evil gennii will play so many pranks with her that she will go to the bottom one of these days."
In his mind her days were already numbered. Risks were growing so great he planned to transfer her cargo to the collapsible iron boat he had designed in Washington and had ordered specially built at Harpers Ferry. With that in mind, he killed six elk on June 2, intending to use their skins for covering his invention. That same day a grizzly pursued Charbonneau, who managed to dive into a dense copse and hide while Drouillard killed the beast with a shot in the head. So there was much to think about on June 2, but at twilight all was driven from the explorers' minds by what looked like a shocking geographic betrayal.
Up ahead, where the bluffs on the south lost some of their height and the bottomlands widened, the river split into two branches of approximately equal size. Impossible. The only major northern tributary the Hidatsas had told Lewis and Clark about was The River That Scolds at All Others. The Corps had passed that stream, after renaming it the Milk, nearly four weeks before. Moreover: the sole tributary the Indians had mentioned as entering the main river from the south was the Musselshell. They had not talked of the Judith. Only of the Musselshell, which was unmistakably behind them. Yet here were two streams. One had to be the Missouri's. One had to be a branch, perhaps the Missouri north fork, as shown on the King-Arrowsmith map. Which was which? Why hadn't the Indians warned them?
It was essential they learn immediately. For if they chose wrong and ended up stranded far from the Columbia headwaters, there would not be time to come back and try again, even if the discouraged soldiers were willing to make a second effort. Choose now. Choose right. Or the Corps of Discovery was finished.
The next morning they moved camp directly below the junction, on the north side of the main river. While canoe and land parties made preliminary investigations of both streams, the captains scrambled to the top of the wedge of land separating the branches. This led to the discovery that a pretty little creek sliced through the wedge to enter the north fork a few miles above the junction. Because of that creek's bordering hills, they could not get a view of the course the north branch followed. But they did have a magnificent panorama of what lay to the south and southwest. First came the looming, snow-streaked peaks known today as the Highwoods. Beyond and somewhat to the west of the isolated Highwoods another stretch of peaks extended dimly a little west of north until their snowy summits disappeared beneath the horizon. The first ridge of the Rockies at last! Or so Lewis and Clark supposed.
With the supposition came, like a flash of sunlight, a possible solution to the problem of identities. The Hidatsas had said that after issuing from the easternmost ridge of the Rockies, the Missouri flowed northeast a hundred or more miles, passing a thunderous waterfall before veering fully east to pick up the Musselshell, The River That Scolds, and the Yellowstone.  The windings of the south fork and the gentle undulations of the land rolling out from the skirts of the peaks prevented the captains from tracing the course of the river far enough to know beyond doubt that it was the stream of which the Hidatsas had spoken—the Missouri, whose headwaters they had been ordered to find as a prelude to reaching the Pacific. Yet what else could it be?
Well, there was that troublesome junction, that extra stream, just behind their heels. Why hadn't the Indians mentioned it? What was it?
Probably Clark offered the explanation. During the spring, after talking about geography with the Hidatsas (also known as the Big Bellies), he had drawn on his conjectural map of the West a dotted line labeled "The War Path of the Big Bellies." This was the route the Hidatsa warriors used in reaching the horse-rich Snake and Flathead Indians of the Rockies. The fast-traveling raiders disdained the labor and slowness of boats. Instead, they rode directly across the plains, well south of the Missouri, until they intersected the river at the awesome landmark Clark had labeled "Falls" on his map. The worrisome river junction lay well north of the war path. Quite possibly the Hidatsas had neither seen nor heard of the junction. So of course they had said nothing about it. 
Back to camp Lewis and Clark went, satisfied with their conjectures. And there they found that the enlisted men had developed a contrary logic of their own. For well over two thousand miles they had been following a notoriously turbid river whose bottom was thick with silt and whose surface had a heavy, undulant motion. The northern branch retained those characteristics. The southern was so transparent it was possible to see flat stones and gravel in its bottom. Its surface was swift, sleek, and sparkly. How could a stream that looked like crystal be the famed Big Muddy?
This was a military expedition and the captains could have ordered, without explanation, the contingent to go where the officers chose. But to start the men along a route they clearly believed might be disastrous would destroy the high morale that had been a major element in the expedition's success so far. Consequently, Lewis and Clark replied patiently to the demurrers, pointing out that streams recently emerged from the mountains—and that description certainly seemed to fit the south fork—retained their clear, dancing appearance for several miles. By contrast, the north fork, which by measurement had turned out to be smaller than the south, was so laden with silt that it must have flowed a long distance through the plains. Perhaps it did not reach as far west as the mountains at all. If that were true, how could the expedition reach the Columbia by following it? Besides, what of all the things the Indians had said?
The men weren't satisfied by these arguments. Nor were the scouts who had been sent out that morning any help. The depth of both the south and north river troughs and the rolling nature of the plains had kept them from developing any firm information about the rivers' distant courses. Clearly a broader reconnaisance was needed.
In the end it was arranged that Clark, Sergeant Gass, Shannon, the Field brothers, and York would follow the south fork until they were sure of its trend. Meanwhile Lewis would go up the north fork with Sergeant Pryor, Shields, Windsor, Cruzatte, Drouillard, and Lepage. The seventeen men who stayed in camp under Sergeant Ordway would hunt, both for food and for deer and elk hides the Corps could sew into clothing and use for covering the iron boat frame. In particular, they all needed moccasins for feet torn and bruised by towing the boats barefooted over miles of stones and thorns. And all of them were still cheerful. No, it would not have done to shake morale such as that by arbitrarily ignoring the men's opinions.
The new reconnaisance was conducted during a miserable period of mixed rain and snow.  Clark's party was the luckier in that they were able to stay dry in an abandoned Indian tepee during their first night out. There was probably considerable kidding of Joseph Field, who escaped a grizzly's charge by the thinnest of margins. The next day the scouts got even, in their own minds, by slaying three huge bears and dining on part of one. And all the while the river trench kept pulling them southwest. The Missouri for sure, Clark announced, though the others still had reservations. Turning around the next day, the little party made a forced march back to the junction, carrying with them, as raw material for more clothing, the hides of seven deer they killed along the way.
Lewis's trip was more arduous. At times thirst and wind-whipped rain drove his group off the plains into the bottom of the north fork. Not for long, however. The valley was narrow; in many places steep ridges dropped into the water. To get around such places they would either angle across the faces of the bluffs or clamber back to the plains. At night they sought shelter in thickets of riverbank willows. The brush broke the wind but did little to turn the rain.
By June 6 (the day Clark returned to the junction), Lewis felt confident the fork he was following angled too far north of west to strike the landmarks the Hidatsa had said lay along the true Missouri. To make doubly sure, he sent Pryor and Windsor ahead to a distant hill to take additional sightings. While waiting for them, he and the others constructed two small rafts. Floating down the river would be easier than walking either along its banks or atop the wind-swept, ravine-creased plains. Or so they assumed. When Pryor and Windsor returned about noon with word that the river continued north of west, they loaded their rafts for the return journey. The flimsy contraptions bucked and tilted. After soaking the elkskins they were taking to camp and almost losing their guns, they abandoned the effort, to spend another "disagreeable and wrestless night" without shelter.
The next day they tried to negotiate the faces of bluffs they had crossed readily on the way upstream. This time, however, the soaked ground was as slippery as bear oil. One pass turned out to be especially dangerous. (By "pass" Lewis meant a narrow, horizontal ledge and not a low saddle between hills.) When he tried to walk along it, his feet flew out from under him "and but for a quick and fortunated recovery by means of my espontoon I should been precipitated into the river down a craggy pricipice about ninety feet." (Shades of the knife thrust that had saved him from a disastrous fall near the Tavern, a short time after the expedition had started up the Missouri!) Behind him Windsor landed belly down on the same slippery ledge, his right arm and right leg dangling into space. Calmly Lewis coaxed the frightened soldier ahead to safety and then ordered the others to backtrack, descend the bluff, and wade around its base in ice-cold water breast deep. Lewis and Windsor soon joined them, and they walked dourly through mud, water, and wet brush until, like Clark's party, they found shelter in an old Indian lodge.
At about ten o'clock the next morning, June 8, the sun broke through the clouds. Listening to the songs of an almost incredible number of birds, Lewis felt his spirits soaring. He had found a new river, and it needed a name. Clark had used Judith for a river he fancied, so Lewis decided to lay claim to this one and call it Maria's River in honor of Maria Wood, a cousin of his. Its turbulent and muddy water, he admitted, "illy comported with the pure celestial virtues and amiable qualifications of that lovely fair one." It was a noble river, nevertheless, passing through a rich, picturesque landscape where magnificent animals abounded. More important, it opened the way to a valuable fur country (that fantasy again!). Maria. Maria. But Meriwether Lewis, unlike William Clark with his Judy, never did marry her or anyone else.
Having compared notes, the captains announced their decision for the shallow, swift-flowing south fork. To gain manpower for handling the boats in the difficult current, they decided to leave the red pirogue hidden in a stand of thick cottonwood timber on an island near the junction. Part of its cargo, together with the heaviest material in the white pirogue and in the dugouts, would be cached in a slender-necked, deep, bulbous pit dug into a dry spot well back from the river. Whatever essentials the red boat had carried would be distributed as evenly as possible among the remaining craft.
Lewis carefully explained to a meeting of the men the evidence prompting the choice. The soldiers agreed to go wherever they were taken, but they were still not satisfied. With Cruzatte, the best riverman in the group, acting as their spokesman, they politely listed once more their reasons for favoring the familiar-looking north fork. To placate them once again, the captains agreed that Lewis and a small group of scouts would go up the south fork ahead of the main party to determine whether the Great Falls of the Missouri did indeed lie up that branch. If they did not find the cataract within a reasonable distance, they would return and halt the boats before the error became irremediable.
That weight off their minds, the soldiers, most of whom had spent the day dressing skins for clothing, "passed the evening dancing singing &c and were extreemly cheerful." Lewis, though, was feeling unwell. Nervous stomach? Possibly. He seldom suffered from such an ailment, but this day the expedition was standing on the threshhold of what could be its most serious crisis to date. Anyway, he purged himself with a dose of salts and told his diary that the action brought him relief.
His was not the only ailment. Sacagawea, normally active and helpful, awoke wan and listless in the leather tent the morning after Lewis's purge. It was not a good time to drag. Both captains were absorbed in trying to bring order to the major adjustments facing the party. Rain-wet baggage had to be spread out and dried. The earth from the six-foot-deep cache had been placed on skins, lugged away, and scattered where it would not be noticed by passing Indians. Now the cache itself had to be lined with sticks and grass so the materials placed in it would stay dry. Items to be stored were segregated from those that would go. The former included bundles of furs, kegs of pork, hulled corn, powder and lead for bullets, traps, and all but the most essential tools—altogether about half a ton of material, Sergeant Gass estimated. 
Because the blacksmiths worked up to the last minute putting the necessary tools into shape and repairing firearms, including Lewis's airgun, a second, smaller cache had to be prepared for the forge and bellows. A duplicate store of powder and lead also went into the second pit, so that if Indians found and rifled one cache, the other might remain to fortify the explorers on their return journey. Meanwhile the big red pirogue had to be inched into its island hiding place and covered with boughs.
At some point during the hurly-burly, Clark noticed that Sacagawea was suffering from more than an ordinary indisposition. Severe pains in the lower abdomen. Lips dry and feverish. Opening his razor-sharp lancet, he slit into a vein on the inside of her elbow. After letting as much blood flow as he deemed wise, he applied a tourniquet. The process probably terrified the young mother, even though she must have heard about and perhaps have seen the operation performed on male members of the expedition. But she had complete confidence in Clark, which may be why he rather than Lewis did the bloodletting. 
All the principals in the performance were in the leather tepee that night, June 10. As Lewis listened to Sacagawea stir when the baby whimpered, he must have thought, before dropping asleep, how deeply they would depend on her when they met some of her horse-owning tribespeople up the river, as surely they would. As surely they had to. But he was too tired to worry for long. After all, didn't the nation's best physicians consider bleeding a sovereign remedy?
The next morning, after a concerned glance at the pallid young woman, he shouldered his pack and started up the south fork with Drouillard, Gibson, Goodrich, and Joseph Field to prove in fact what he already knew from logic: here was the Missouri.