• May 14–20, 1804 Preparations, including hiring boatmen
Camp Dubois, Illinois
• May 21–June 1, 1804
• Supply base
Fort Kaskaskia, Illinois
• June 3–5, 1804
• Met with territorial governor William Henry Harrison; hired George Drouillard as a hunter and interpreter
Ohio River near Smithland, Kentucky
• July 15, 1804
• Met with Aaron Burr, who was on his way downriver and provided Lewis and Clark with valuable intelligence
Falls of the Ohio (Louisville), Kentucky
• August 1–3, 1804
• Picked up a flatboat and supplies
Clarksville, Indiana
• August 11–14, 1804
• Hired additional crew members
Harmonie, Indiana
• September 26, 1804
• Met with William Henry Harrison again; received advice and supplies
Vincennes, Indiana
• December 15, 1804
• Met with territorial governor William Henry Harrison again; discussed plans for the expedition with Native American leaders; picked up supplies
Kaskaskia, Illinois
• January 19–21, 1805
• Met with territorial governor William Henry Harrison; discussed plans for the expedition with Native American leaders; picked up supplies
St. Louis, Missouri
• February 23–March 9, 1805
• Final preparations, including hiring keelboatmen
Wood River, Illinois
• April 8–21, 1805
• Built a keelboat; hired additional crew members
Alton, Illinois
• May 3–4, 1805
• Met with William Clark’s brother, John; hired additional crew members
St. Charles, Missouri
• May 12–20, 1805
• Final preparations; met with Native American leaders; picked up supplies
Fort Bellefontaine, Missouri
• May 25–26, 1805
• Picked up supplies; received permission from Spanish authorities to enter their territory
Council Bluffs, Iowa
• July 19–August 3, 1805
• Built Fort Atkinson; winter quarters for the expedition
Mandan Villages, North Dakota
• November 2, 1805–April 7, 1806
• Winter quarters for the expedition; built Fort Mandan; learned about the local Native American tribes and their culture; hired Toussaint Charbonneau and his Shoshone wife, Sacagawea, as interpreters
Great Falls of the Missouri, Montana
• June 13–July 15, 1806
• Portaging around the Great Falls of the Missouri River
Lemhi Pass, Idaho
• August 12–17, 1806
• Crossed the Continental Divide; met with Shoshone Indians and obtained horses
Camp Fortunate, Idaho
• September 23–October 6, 1806
• Rebuilt canoes and supplies; hunted for food
Celilo Falls, Oregon
• November 4–24, 1806
• Portaging around Celilo Falls on the Columbia River
Fort Clatsop, Oregon
• December 7, 1805–March 23, 1806
• Winter quarters for the expedition; built Fort Clatsop; met with local Native American tribes and learned about their culture
Cape Disappointment, Washington
• March 24–27, 1806
• Reached the Pacific Ocean
Fort Clatsop, Oregon
• March 28–April 7, 1806
• Returned to Fort Clatsop; prepared for the return journey
Celilo Falls, Oregon
• April 11–14, 1806
• Portaging around Celilo Falls on the Columbia River
Lemhi Pass, Idaho
• June 30–July 2, 1806
• Crossed the Continental Divide
Mandan Villages, North Dakota
• August 14–22, 1806
• Reunited with Toussaint Charbonneau and Sacagawea; picked up supplies
Council Bluffs, Iowa
• September 11–22, 1806
• Stopped to rest and hunt; met with Native American leaders; picked up supplies
Bellevue, Nebraska
• September 25, 1806
• Met with William Clark’s brother, John
St. Louis, Missouri
• September 23, 1806
• Arrived back in St. Louis; completed their expedition