Thomas Jefferson hoped the Corps of Discovery would provide a window onto the West. The men of the Expedition were to observe and record everything, from the languages of the Indians to the dates when plants flower. In fulfilling Jefferson’s charge, the explorers became capable amateur scientists.

In preparation for the journey, Lewis studied with the best scientists in Philadelphia. As the Corps traveled, the men of the Expedition pressed plants, dried the fur of animals, and wrapped them all in oilcloth to protect them from rain and river water. They wrote detailed descriptions and sometimes drew what they saw around them. Clark sketched the courses of the rivers.

In 1806, back in Washington, Lewis laid out the map Clark had drawn and he and Jefferson looked onto the West. It would be many years before the rest of the world had the same opportunity. The official Expedition journals and Clark’s map were not published until 1814, eight years after the journey.

The science of the Expedition still allows us, 200 years later, to peer into the West of the early 19th century.