Lewis and Clark Expedition

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Officially known as the Corps of Discovery and commissioned by President Thomas Jefferson, this was the first overland expedition by the United States to reach the Pacific Ocean.

President Jefferson was particularly interested in finding an all-water route to the Pacific Northwest as a way for facilitating trade and colonization, a task he entrusted to two seasoned military men, Meriwether Lewis and William Clark. His instructions to the explorers were straightforward:

“The object of your mission is to explore the Missouri River, & such principle stream of it, as, by its course and communication with the waters of the Pacific ocean, whether the Columbia, Oregon, Colorado or any other river may offer the most direct & practicable water communication across this continent for the purpose of commerce.”

The expedition began in St. Louis, Missouri, in May 1804 and would conclude at the same location two years later. The explorers followed the Missouri River to the Continental Divide, then used canoes to descend the mountains via the Clearwater, Snake and Columbia Rivers. They sighted the Pacific Ocean for the first time on November 7, 1805, and spent a brutally cold and stormy winter on the Oregon Coast near present day Astoria.

Throughout the entire journey, Lewis and Clark studied the continent’s geography, wildlife and Native American tribes. (Many species and locations in the Pacific Northwest still bear their names.) Both kept detailed journals which were later published and helped pave the way for American expansion westward.

Related Features: Clark and the Whale | Fort Clatsop National Monument | Lewis and Clark and Inquiry in Action | Lewis and Clark National Historic Park