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Historical Background

Advent of spring

Near the end of March, as the weather moderated, the ice broke up in the river and huge flocks of ducks and geese were seen winging their way northward. Also witnessed were the efforts of local Indians to replenish their food supply from buffalo that had become stranded on ice floes as they tried to cross the Missouri. The natives demonstrated extraordinary dexterity in jumping from one cake of ice to another. Others retrieved from the water dead bodies of the animals as they floated down. Clark noted that the plains near Fort Mandan on both sides of the river were on fire. The Indians set them to the torch early in the spring to bring green grass, which provided food for their horses and attracted buffalo.

This painted Indian buffalo robe, now in the Peabody Museum at Harvard University, is probably the oldest one in existence. Lewis and Clark obtained from the Mandans and sent t back to President Jefferson in the spring of 1805. Depicted is a 1797 battle between the Mandans-Minitaris and the Teton Sioux Arikaras. (Peabody Museum.)

Preparations for departure

The arrival of spring meant that the time was near to push on westward and that the necessary preparations had to be made. Because the keelboat was considered too large for use farther upriver and was to return to St. Louis, one of the first tasks was to build six dugout canoes to supplement the two pirogues, which late in February were chopped out of the ice, along with the keelboat, and brought up on shore so they could be readied for the journey. The cottonwoods near Fort Mandan were not large enough for the canoes, so on February 28 Lewis and Clark sent Sergeant Gass and 16 men to locate some of desirable size and build the canoes. Large trees were found 5 miles to the north of Fort Mandan near the mouth of the Knife River. The canoes were completed in about 3 weeks, and on March 20 and 21 were carried a short distance to the Missouri and then paddled down to the fort. Before departure, the swivel cannon that had originally been mounted on the bow of the keelboat and removed to fortify Fort Mandan was dismounted and probably set up in one of the pirogues.

Another major effort preparatory to leaving Fort Mandan was numbering, labeling, and packing the extensive collection of zoological, botanical, and ethnological specimens and artifacts that had been obtained so far for dispatch to President Jefferson on the keelboat. [81] The shipment consisted of four boxes, one trunk, and three cages. The cages contained a live prairie dog, a sharp-tailed grouse, and four magpies. Included in the boxes and the trunk were the pelts, horns, and skeletons of various animals; dried plant, soil, mineral, and insect specimens; Mandan and Minitari artifacts and items such as plain and decorated buffalo robes, an earthen pot, bow and quiver of arrows, an ear of corn, and tobacco seed; and Arikara tobacco and tobacco seed. [82] Labels included the date and place obtained and brief description. All told, the collection consisted of a wealth of information about the flora and fauna and native peoples of the West.

Also sent back on the keelboat were various letters, reports, dispatches, and maps addressed to Jefferson and Secretary of War Henry Dearborn. [83] The major topics treated in the letters and reports were descriptions of Indian tribes that had already been encountered and those to the west of the Mandan villages, mainly based on Minitari data, as well as geographical information. The dispatches included a large, extensively annotated table prepared by Clark that represented the first summary of the trans-Mississippi tribes—an ethnological classic. [84] One of Clark's maps showed the detailed course of the Missouri as far as Fort Mandan and a general map of the country west of there to the Pacific between the 34th and 54th parallels, based to a considerable extent on data provided by the Minitaris. [85]