Lewis and Clark: "We send from this place with dispatches."
The early weeks of the ascent of the Missouri brought the Corps of Discovery through a generally pleasing landscape with innumerable opportunities to study both known and new features and wonders. The captains avidly collected, examined, and described botanical, zoological, and mineral specimens. They made countless measurements and astronomical observations, occasionally interrupting these endeavors to visit scattered settlements or to compare notes with passing traders.
The explorers hunted and battled the river currents and the inevitable insects and travel-related illnesses. Security measures to avoid conflicts with the Indians were a priority for Lewis, as was a firm disciplinary approach to infractions of the rules of the expedition.
On July 21, 1804, the explorers reached the mouth of the Platte River, more than six hundred miles from Wood River, a significant step on the westward journey, and Indian country. The first encounter with its residents - a group of Otos and Missouris - occurred in early August. Lewis delivered the message of their new Great Chief in Washington, who assured them of friendship and benefits of trade in exchange for peace and cooperation. August twentieth marked the loss of the only member of the Corps of Discovery who did not complete the journey to the Pacific and back. Sergeant Charles Floyd died after several days of illness, probably of a ruptured appendix.Throughout the early fall of 1804 the expedition traveled in high plains, discovering such new and interesting wildlife as prairie dogs, pronghorns, and jackrabbits, and experiencing tense encounters with several group of Indians, including the Teton Sioux. The captains managed to avert hostilities with their usual assurances of the benefits of becoming part of the United States, by bestowing gifts, and by standing firm when tribal leaders threatened violence to express dissatisfaction with these offerings. These confrontations were complicated, not only by the captains' lack of knowledge of relations and rivalries among the tribes, but by the shortcomings of the available translators.
The expedition arrived at the villages of the Mandan and allied Hidatsa Indians at the end of October where the captains decided to spend the winter of 1804 - 1805. These settlements were known as trading centers, visited by Indians from many tribes of the Northern Plains as well as by representatives of European and Canadian trading companies.
The Corps of Discovery was well-received, and relations with the Mandans were
generally cordial with occasional problems arising from consequences of shifting
inter-tribal alliances imperfectly understood by the white Americans. Here a
Canadian trader, Toussaint Charbonneau, signed on as an interpreter for the
Western journey. He brought with him his young pregnant Shoshone wife Sacagawea, who,
with her language skills and geographical knowledge, became one of the most
valuable and famous members of the expedition. Their son Jean-Baptiste, known as
Pomp, or Pompey, was born in February and accompanied his parents to the Pacific
and back to the Mandan villages.
The explorers spent the months at Fort Mandan hunting, trading, building additional canoes, and repairing equipment. The captains focused on research and planning for what lay ahead. By early April 1805, the party was ready to press on to the falls of the Missouri with two pirogues and six small canoes and then to the "rocky mountains."
Reports of their stay at Mandan and plans for the next phase of the journey returned with the large keelboat and its crew to St. Louis and began to appear in newspapers by the early summer of 1805.