The mouth of the Platte River was reached on July 21st, and the next day Lewis held a council with the Ottoes and Missouri Indians, and named the site Council Bluffs. At each of these meetings between Lewis and the Indians the white man would explain that this territory was now part of the United States, would urge the tribes to trade with their new neighbors, and then present them with gifts of medals, necklaces, rings, tobacco, ornaments of all sorts, and often powder and arms.
The Indians were friendly and each day taught the white men something new. Both Captain Lewis and Lieutenant Clark had seen much of the red men on the frontier, but now they were in a land where they found them in their own homes. They grew accustomed to the round tepees decorated with bright-colored skins, the necklaces made of claws of grizzly bears, the head-dresses of eagle feathers, the tambourines, or small drums that furnished most of their music, the whip-rattles made of the hoofs of goats and deer, the white-dressed buffalo robes painted with pictures that told the history of the tribe, the moccasins and tobacco pouches embroidered with many colored beads. Each tribe differed in some way from its neighbors. For the first time the explorers found among the Rickarees eight-sided earth-covered lodges, and basket-shaped boats made of interwoven boughs covered with buffalo skins.
Game was plentiful as they went farther up the Missouri River. At first no buffaloes were found, but bands of elk were seen, and large herds of goats crossing from their summer grazing grounds in the hilly region west of the Missouri to their winter quarters. Besides these were antelopes, beavers, bears, badgers, deer, and porcupines, and the river banks supplied them with plover, grouse, geese, turkeys, ducks, and pelicans. There were plenty of wild fruits to be had, and they lived well during the whole of the summer. They traveled rapidly until the approach of cold weather decided them to establish winter quarters on October 27th.
They pitched their camp, which they called Fort Mandan, on the eastern shore of the Missouri, near the present city of Bismarck. They built some wooden huts, which formed two sides of a triangle, and a row of pickets on the third side, to provide them with a stockade in case of attack. They found a trader of the Hudson's Bay Company near by, and during the winter a dozen other traders visited them. Although they appeared to be friendly, Captain Lewis was convinced that the traders had no desire to see this United States expedition push into the country, and would in fact do all they could to prevent its advance. The Indians in the neighborhood belonged to the tribes of the Mandans, Rickarees, and Minnetarees. The first two of these tribes went to war early in the winter, but peace was made through the efforts of Captain Lewis. After that all the Indians visited the encampment, bringing stores of corn and presents of different sorts, in exchange for which they obtained beads, rings, and cloth from the white men. Here Captain Lewis learned a curious legend of the Mandan tribe. They believed that all their nation originally lived in one large village underground near a subterranean lake, and that a grape-vine stretched its roots down to their home and gave them a view of daylight. Some of the more adventurous of the tribe climbed up the vine, and were delighted with the sight of the earth, which they found covered with buffaloes and rich with all kinds of fruits. They gathered some grapes and returned with them to their countrymen, and told them of the charms of the land they had seen. The others were very much pleased with the story and with the grapes, and men, women and children started to climb up the vine. But when only half of them had reached the top a heavy woman broke the vine by her weight, and so closed the road to the rest of the nation. Each member of this tribe was accustomed to select a particular object for his devotion, and call it his "medicine." To this they would offer sacrifices of every kind. One of the Indians said to Captain Lewis, "I was lately the owner of seventeen horses; but I have offered them all up to my 'medicine,' and am now poor." He had actually loosed all his seventeen horses on the plains, thinking that in that way he was doing honor to his god.
Almost every day hunting parties left the camp and brought back buffaloes. The weather grew very cold in December, and several times the thermometer fell to forty degrees below zero. As spring advanced, however, the weather became very mild, and as early as April 7, 1805, they were able to leave their camp at Fort Manden and start on again. The upper Missouri they found was too shallow for the large barge they had used the previous summer, so this was now sent back down the river in charge of a party of ten men who carried letters and specimens, while the others embarked in six canoes and two large open boats that they had built during the winter. So far the country through which they had passed had been explored by a few Hudson's Bay trappers, but as they now turned westward they came into a region entirely unknown, which they soon found was almost uninhabited.
The party had by this time three interpreters, one a Canadian half-breed named Drewyer, who had inherited from his mother the Indian's skill in woodcraft, and who also knew the language of the white explorers. The other two were a man named Chaboneau and his wife, a young squaw called Sacajawea, the "Bird-woman," who had originally belonged to the Snake tribe, but who had been captured in her childhood by Blackfeet Indians. This Indian girl had married Chaboneau, a French wanderer, who like many others of his kind had sunk into an almost savage state. As the squaw had not forgotten the language of her native people the two white leaders thought she would prove a valuable help to them in the wild country westward, and persuaded her and her husband to go on with them.
As the weather was fine the party traveled rapidly, and by April 26th reached the mouth of the Yellowstone. They were now very far north, near the northwest corner of what is the state of North Dakota. Game was still plentiful but the banks of the river were covered with a coating of alkali salts, which made the water of the streams bitter and unpleasant for drinking. Occasionally they came upon a deserted Indian camp, but in this northern territory they found few roving tribes. When there was a favorable wind they sailed along the Missouri, but most of the time they had to use their oars. Early in May they drew up their birch canoes for the night at the mouth of a stream where they found a large number of porcupines feeding on young willow trees. Captain Lewis christened the stream Porcupine River. Here there were quantities of game, and elk and buffalo in abundance, so that it was an easy matter to provide food for all the party.
Now they were continually coming upon new rivers, many of them broad, with swift-flowing currents, and all of them appealing to the love of exploration. The Missouri was their highroad, however, and so they simply stopped to name the different streams they came to. One they passed had a peculiar white color, and Captain Lewis called it the Milk River. The country along this stream was bare for some distance, with gradually rising hills beyond.
The game here was very plentiful and the buffaloes were so tame that the men were obliged to drive them away with sticks and stones. The only dangerous animal was the grizzly bear, a beast that never seemed to know when he had had enough of a fight. One evening the men in the canoes saw a large grizzly lying some three hundred paces from the shore. Six of them landed and hid behind a small hillock within forty paces of the bear; four of the hunters fired, and each lodged a ball in the bear's body. The animal sprang up and roared furiously at them. As he came near them the two hunters who had not yet fired gave him two more wounds, one of which broke a shoulder, but before they had time to reload their guns, the bear was so near them that they had to run for the river. He almost overtook them; two jumped into the canoes; the other four separated, and hiding in the willows fired as fast as they could reload their guns. Again and again they shot him, but each time the shots only seemed to attract his attention toward the hunters, until finally he chased two of them so closely that they threw away their guns, and jumped down a steep bank into the river. The bear sprang after them, and was almost on top of the rear man when one of the others on shore shot him in the head, and finally killed him. They dragged him to shore, and found that eight balls had gone through him in different directions. The hunters took the bear's skin back to camp, and there they learned that another adventure had occurred. One of the other canoes, which contained all the provisions, instruments, and numerous other important articles, had been under sail when it was struck on the side by a sudden squall of wind. The man at the helm, who was one of the worst navigators of the party, made the mistake of luffing the boat into the wind. The wind was so high that it forced the brace of the square-sail out of the hand of the man who was holding it, and instantly upset the canoe. The boat would have turned upside down but for the resistance of the canvas awning. The other boats hastened to the rescue, righted the canoe, and by baling her out kept her from sinking. They rowed the canoe to shore and the cargo was saved. Had it been lost the expedition would have been deprived of most of the things that were necessary for its success, at a distance of between two and three thousand miles from any place where they could get supplies.
On May 20th they reached the yellowish waters of the Musselshell River. A short distance beyond this Captain Lewis caught his first view of the Rocky Mountains, one of the goals toward which they were tending. Along the Musselshell the country was covered with wild roses and small honeysuckle, but soon after they came into a region that was very bare and dry, where both game and timber were scarce, the mosquitoes annoying, the noonday sun uncomfortably hot, and the nights very cold. The Missouri River, along which they were still traveling, was now heading to the southwest. They were near the border of the present state of Idaho when they passed several old Indian camps, most of which seemed to have been deserted for five or six weeks. From this fact they judged that they were following a band of about one hundred lodges, who were traveling up the same river. They knew that the Minnetarees of the Missouri often traveled as far west as the Yellowstone, and presumed that the Indians ahead of them belonged to that tribe. There were other evidences of the Indians. At the foot of a cliff they found the bodies of a great many slaughtered buffaloes, which had been hunted after the fashion of the Blackfeet. Their way of hunting was to select one of the most active braves, and disguise him by tying a buffalo skin around his body, fastening the skin of the head, with ears and horns, over the head of the brave. Thus disguised the Indian would take a position between a herd of buffalo and the precipice overlooking a river. The other hunters would steal back of the herd, and at a given signal chase them. The buffaloes would run in the direction of the disguised brave, who would lead them on at full speed toward the river. As he reached the edge he would quickly hide himself in some crevice or ravine of the cliff, which he had chosen beforehand, and the herd would be left on the brink. The buffaloes in front could not stop being driven on by those behind, who in their turn would be closely pursued by the hunters. The whole herd, therefore, would usually rush over the cliff, and the hunters could take their pick of hides and meat in the river below. This method of hunting was very extravagant, but at that time the Indians had no thought of preserving the buffaloes. One of the rivers Lewis passed in this region he named the Slaughter River, on account of this way of hunting.