A Brief History
Courtesy of the National Park Service
In 1804 -1806, President Thomas Jefferson commissioned Meriwether Lewis and William Clark to lead an expedition on an epic journey to explore the headwaters of the Missouri River and find an overland route to the Pacific Ocean by way of the Columbia River. The Corps of Discovery departed Camp DuBois near Wood River, Illinois, on May 14, 1804, and proceeded up the Missouri River using a keelboat and two pirogues (canoe-like boats).
After several councils with Indian tribes on the lower Missouri River, and the unfortunate death of Sergeant Floyd near present Sioux City, Iowa, the party reached the Knife River Indian villages, near present Washburn, North Dakota. There they built Fort Mandan and spent a productive winter gathering information about the Indian tribes and the land to the west. They also recruited as interpreters the Frenchman Toussaint Charbonneau and his Shoshoni wife, Sacagawea.
In the spring of 1805, the permanent party continued up the Missouri River in the pirogues and dugout canoes. After an arduous portage around the Great Falls of the Missouri, they reached the rivers' headwaters. Now on foot, the party encountered a band of Shoshoni Indians, coincidentally led by Sacagawea's brother Cameahwait. The Shoshoni assisted the expedition by providing horses and a guide to cross the rugged Bitteroot Mountains.
After a difficult crossing on what is now known as the Lolo Trail, the party met the friendly Nez Perce Indians. They left their horses with the Indians and once again made canoes. Navigating down the Clearwater, Snake, and Columbia Rivers, the Corps of Discovery reached the Pacific Ocean in November 1805. The party built Fort Clatsop on the south side of the Columbia River near present Astoria, Oregon, where they spent a cold, rainy winter.
In the spring and summer of 1806, the expedition made their way back across the mountains, explored several major rivers in present day Montana, and made their way back down the Missouri River to St. Louis, arriving on September 23, 1806.