Scientific Encounters

Clark's drawing and description of a sage grouse
William Clark's drawing and description of a sage grouse

Missouri History Museum

It has been described as "the greatest camping trip of all time" - a voyage steeped in adventure. It was an exercise in what became known as Manifest Destiny, which carried the American flag to the Pacific. The Lewis and Clark Expedition was these, but was also significant for its scientific resource descriptions.

Between 1804 and 1806, Lewis and Clark made the first systematic reports of the Missouri River. These reports contained measurements and observations of its course and its surrounding flora, fauna, tributaries and inhabitants. They also documented their observations in the Rocky Mountains and the Pacific Northwest. Lewis and Clark described at least 178 plants and 122 animals - including mammals, birds, reptiles and fish. They made the first attempt at a systematic record of the meteorology of the West. They also attempted to determine the latitude and longitude of significant geographical points.

On the Missouri River, Lewis focused on the the animals, rocks, trees and grasses. How fast was the current? How high were the cliffs? Was that bird or plant different from one known in the East? They encountered and described eastern woodrats, grizzly bears, and prairie dogs. They saw so many buffalo that at one point they recorded that they had to "club them out of the way." New species that the Corps of Discovery encountered included pronghorn, bighorn sheep, black tailed deer (or mule deer), mountain beaver, long-tailed weasel, mountain goat, coyote and various species of rabbit, squirrel, fox and wolf. They sent back descriptions, zoological specimens, and even a few live animals. One of the animals sent to President Jefferson in 1805 was a "barking squirrel," or black-tailed prairie dog. After keeping it for a short while, Jefferson gave the prairie dog to Charles Wilson Peale’s museum in the old Independence Hall building in Philadelphia.

The geographical findings were also significant. They determined the true course of the Upper Missouri and its major tributaries. They found that neither the Missouri nor the Columbia were navigable to its source, as many had believed. They learned that two north-south mountain systems, the Rockies and the Cascades, represented major barriers. Generally passing through areas that no Europeans had seen, the two dotted their map with names of streams and natural features.

Clark made his scientific mark in the field of cartography. His training consisted in practical surveying and a limited amount of Army mapping. His maps advanced geographical knowledge and stimulated cartographic advances. Particularly important were the three progressively improved maps he drew between 1804 and 1810 of the Western United States and lower Canada. They included his and Lewis's observations, information provided by indigenous contacts, earlier maps of the West, and information from preceding explorers and some who were in the West after the Corps. Historical cartographer Carl I. Wheat said the last was of "towering significance" and was "one of the most influential ever drawn" of the United States.

They made significant additions to the botanical knowledge of the continent. Jefferson thought the voyage would add to the world's supply of food crops and plants beneficial to humankind. He directed them to pay special attention to the climate and conditions under which edible plants were growing. They collected hundreds of plant specimens, recording information on habitat, growth, and use. Lewis and Clark discovered about 128 species new to science, including future state flowers for Oregon, Idaho, and Montana. Their collections would eventually be housed at the Academy of Natural Sciences, where they are held today.

More than a diplomatic and economic journey, the Lewis and Clark Expedition was a well-documented 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 over 200 years later.

This is an updated excerpt from
The Science of the Lewis and Clark Expedition, which was published by Jefferson National Expansion Memorial

Last updated: November 6, 2017