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Scientific Encounters

The Lewis and Clark Expedition was a voyage of high adventure. Between 1804 and 1806, Lewis and Clark made the first systematic reports of the Missouri River based on scientific measurement and observations —not only its course, but also its flora and fauna, depth and current, tributaries and inhabitants. They continued to document their observations in the Rocky Mountains and the Pacific Northwest. Lewis and Clark described for science at least 120 mammals, birds, reptiles and fish, as well as at least 182 plant species. They made the first attempt at a systematic record of the meteorology of the West.

As the expedition began to move up the Missouri River, Lewis focused on the details—the animals, the type of rocks, the trees and grasses—along the route. How fast was the current? How high the cliffs? Was that bird or plant different from one known in the East? Lewis described the animals, including the eastern wood rat—the first animal new to science encountered on the voyage. The explorers encountered fierce grizzly bears that attacked them. Lewis and Clark were fascinated with the little prairie dogs that built huge underground villages. New species they encountered included pronghorn antelopes, bighorn sheep, black tailed deer (or mule deer), mountain beaver, white weasel, mountain goat, coyote and various species of rabbit, squirrel, fox and wolf. In addition to their descriptions, Lewis and Clark sent back a large number of zoological specimens, including a few live ones, as well as skins, bones, skeletons, teeth, talons and horns.

The geographical findings were of outstanding significance. Lewis and Clark determined the true course of the Upper Missouri and its major tributaries. They discovered that a long, instead of short, portage separated it from the Columbia River, which proved to be a majestic stream rivaling the Missouri itself rather than a short coastal river. Neither the Missouri nor the Columbia was found to be navigable to its source, as many had believed. The explorers also learned that, instead of a narrow and easily traversed mountain range, two broad north-south systems, the Rockies and the Cascades, represented major barriers.

Clark’s relatively crude maps, prepared under field conditions, enriched geographical knowledge and stimulated cartographical advances. Of particular importance were the three progressively improved maps Clark drew between 1804 and 1810 of the Western United States and lower Canada. According to historical cartographer Carl I. Wheat, the last of the three (c.1809) was "one of the most influential ever drawn" of the United States.

Lewis and Clark also made significant additions to the botanical knowledge of the continent. Jefferson believed that the voyages of discovery would add to the world's supply of food crops and plants beneficial to humankind. Lewis and Clark collected hundreds of plant specimens and recorded information on their habitats, growth, and uses by American Indians. The explorers discovered about 80 species new to science, including future state flowers for Oregon, Idaho, and Montana, as well as the state grass of Montana. Their collections formed the basis for the first major scientific publication that described and illustrated the plants west of the Mississippi River.

The Lewis and Clark Expedition was a scientific foray. It is this aspect of the expedition, fulfilled in every sense, which sets the Lewis and Clark Expedition apart and plays a major role in its resonance 200 years later.


Source: Scientific Encounters
National Park Service, U.S. Department of the Interior, Public Domain

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