Timeline of the Lewis and Clark Expedition

1803

• January 18: President Jefferson sends a secret message to the U.S. Congress proposing an expedition to the Pacific Northwest.
• February 22: The House and Senate approve Jefferson's request.
• March 15: Lewis travels to the U.S. Army arsenal in Harper's Ferry, Virginia to procure arms and ammunition for the expedition.
• April 19: Lewis arrives in Lancaster, Pennsylvania where he studies the use of the sextant and chronometer for celestial navigation.
• April 30: James Madison, Secretary of State, and Robert R. Livingston, U.S. Minister to France, reach an agreement to purchase the Louisiana Territory from France for $15 million.
• May 17: Lewis leaves Lancaster and travels to Philadelphia to study medicine, anatomy and botany under the day's leading experts. During his three-week stay, he buys supplies and equipment as well as gifts for the Indians he expects to encounter.
• June 19: Lewis writes to William Clark inviting him to co-lead the expedition.
• June 20: President Jefferson sends Lewis instructions for exploring the Louisiana Territory.
• July 4: The proposed Louisiana Purchase Treaty is announced in Washington, D.C.
• July 15: Lewis arrives in Pittsburgh, Pennsylvania, to direct the construction of a 55-foot keelboat with a 32-foot mast and benches for 22 oarsmen. He also purchases a pirogue over 40 feet long.
• July 18: Clark writes to Lewis accepting his invitation.
• August 31: After more than a month of delays, the keelboat is completed and immediately loaded. With a crew of 11, Lewis heads down the Ohio River.
• September 1: Lewis documents the first day of travel, beginning what becomes the Journals of the Lewis & Clark Expedition.
• October 15: Lewis rendezvous with Clark in Clarksville, Indiana territory. Clark is accompanied by his African-American slave York. Over the next two weeks, they select nine civilians from a field of volunteers.
• October 20: The U.S. Senate ratifies the treaty for the Louisiana Purchase.
• November 15: While the Corps camps at the confluence of the Ohio and Mississippi Rivers, Lewis and Clark practice determining longitude and latitude using their surveying instruments.
• November 28: The expedition arrives at the U.S. Army post at Kaskaskia, Illinois, where they recruit more men.
• December 6: Lewis travels by horseback to St. Louis in present-day Missouri intending to spend the winter procuring more supplies.
• December 12: Clark arrives at the site of the expedition's winter encampment on the Mississippi River above St. Louis in Illinois. The construction of Camp Dubois begins the next day.
• December 20: France transfers the Louisiana Territory to the U.S., which takes possession on December 30.

  1804

• March 9: Lewis attends ceremonies in St. Louis witnessing the formal transfer of the new U.S. territory.
• March 26: To his bitter disappointment, Lewis learns that Clark's commission has been approved but as a lieutenant rather than captain. Despite the difference in rank, a fact withheld from the men, the two share command equally throughout the expedition.
• March 29: Pvts. Shields and Colter are tried for mutiny following a fight in which they threaten Sgt. Ordway's life. Their pleas for forgiveness are accepted.
• March 31: Lewis and Clark hold a ceremony formally inducting 25 recruits into the Corps. Another five men are designated to return on the keelboat the next spring before the "permanent party" crosses the Rocky Mountains.
• April 7: Lewis and Clark travel to St. Louis by canoe to attend a dinner and ball.
• May 14: The Corps of Discovery departs Camp Dubois under Clark's command, its crew more than 40 strong.
• May 16: They reach St. Charles on the Missouri River to await Lewis's return from St. Louis.
• May 17: Pvts. Collins, Hall and Werner are court martialed for being AWOL. Collins, who is convicted of additional charges, receives 50 lashes. The other two have their sentences of 25 lashes suspended.
• May 21: With Lewis and Clark in command, the Corps embarks on the keelboat and two pirogues. During their 2,300 mile trip to the Rockies, the men struggle against the Missouri's current. While sails help when the winds are favorable, most progress is by rowing and either pushing or pulling the heavily-ladened keelboat.
• May 25: About 50 miles from St. Charles, the party passes La Charette, the westernmost Euro-American settlement on the Missouri.
• June 26: The expedition encamps at Kaw Point near the Missouri's confluence with the Kansas River in present-day Kansas, 400 river miles into their journey. As a precaution against a possible attack by the regions's Kansa tribe, the men build a temporary defense, but otherwise they spend several days resting and repairing their boats.
• June 29: During the Corps' stay at Kaw Point, Pvt. Collins is court martialed on charges of stealing whiskey while on guard duty. His sentence is severe, 100 lashes. Pvt. Hall, who is tried for drinking with Collins, receives 50 lashes.
• July 4: To honor Independence Day, Lewis and Clark name Independence Creek near modern-day Atchison, Kansas.
• July 11: The Corps enters present-day Nebraska. Pvt. Willard is caught sleeping on guard duty, a capital offense. He is sentenced the next day to receive 100 lashes in four equal installments.
• July 21: The expedition reaches the confluence of Nebraska's Platte River, 640 miles from St. Louis.
• July 30: The Corps camps near today's Fort Calhoun, Nebraska, on a hill they name Council Bluff.
• August 3: Lewis and Clark meet at Council Bluff with chiefs of the Oto and Missouri tribes. While the chiefs want weapons more than token gifts, the Corps' first attempt at diplomacy is for the most part a success.
• August 4: The party departs, but Pvt. Reed deserts. Two days later, the captains determine Reed is to be brought back dead or alive.
• August 18: Reed is captured and returned for trial. In addition to being sentenced to a flogging in which he is required to run the guantlet four times, Reed is expelled from the Corps. Since banishment to the wilds would be a death sentence, he is allowed to remain with the expedition through the winter.
• August 20: Sgt. Floyd dies, probably from a ruptured appendix. He is the sole casualty of the two-year expedition.
• August 26: The men elect Pvt. Gass sergeant. Pvt. Shannon, the Corps' youngest member, becomes lost while searching for horses stolen by the Indians.
• August 27: The Corps strikes camp in Yankton Sioux territory on the Nebraska side of the Missori near the mouth of South Dakota's James River.
• August 30: Lewis and Clark hold talks with the Yanktons, who want rifles and whiskey. Instead, the tribe is invited to send a delegation to meet with the Great White Father in Washington, D.C.
• September 11: Pvt. Shannon is found on the bank of the Missouri starving and out of ammunition after being lost 16 days.
• September 20: They reach the Missouri's Big Bend in central South Dakota, nearly 1,300 miles from their starting point.
• September 25: Weapons are drawn in a confrontation with the Lakota Sioux near modern-day Pierre, South Dakota. Elder Chief Black Buffalo diplomatically intervenes, averting bloodshed.
• October 13: Pvt. Newman is convicted of mutinous talk and expelled. As with Pvt. Reed, he is permitted to remain with the expedition until the spring.
• October 24: The Corps reaches Mandan Indian territory near present-day Washburn, North Dakota. Over the next few days, they meet with Mandan and Hidatsa chiefs and begin looking for a site for a winter fort.
• November 2: A location for their winter fortification is selected across the river from the main Mandan village. They name the encampment Fort Mandan to honor the tribe. Construction begins.
• November 4: Toussaint Charbonneau, a French fur trader living with the Mandans, is hired as an interpreter. One of Charbonneau's wives, a pregnant 16-year-old Lemhi Shoshone named Sacagawea, is also hired.
• December 24: Fort Mandan is completed.
• December 25: The Corps celebrates Christmas with special food, rum and dancing.

  1805

• February 9: Pvt. Howard returns after dark and scales the fort's wall instead of asking the guard to open the gate. An Indian happens to see this and scales the wall himself. In the last disciplinary trial of the expedition, Howard is charged with a breach of security and is ordered to receive 50 lashes, but Lewis suspends the sentence.
• February 11: Sacagawea gives birth to a son, Jean Baptiste Charbonneau. The boy is nicknamed "Pompy" by Clark.
• April 7: With the arrival of spring, the Corps resumes its journey. The keelboat is sent back down the Missouri with a crew of a dozen men and a shipment for President Jefferson. The "permanent party" travels west in the two pirogues and six dugout canoes.
• April 25: The expedition reaches the confluence of the Yellowstone River in northwestern North Dakota, the Missouris's principal northern tributary.
• April 27: They enter present-day Montana. In the ensuing days, the men sight herds of up to 10,000 buffalo. They also encounter and kill their first grizzly bear.
• May 14: A sudden storm tips a pirogue and many items, including the Corps' journals, spill into the river. Sacagawea calmly recovers most of the items, earning Clark's praise for her quick thinking.
• May 26: Lewis sees the Rocky Mountains for the first time. His initial reaction is joy, but he then considers the serious challenges the snow-covered mountains will pose for his men.
• June 1: In north-central Montana, the Corps comes to an unexpected fork in the river, with one branch flowing from the north, the other from the south. They take a vote on which is the Missouri. Only Lewis and Clark favor the southern route. After days of debate and explorations, another vote yields the same result. Despite their doubts, the men agree to follow the leaders.
• June 13: A scouting party led by Lewis reaches the Great Falls of the Missouri. The discovery proves they have taken the correct course.
• June 17: The men circumnavigate the falls, dragging their canoes and equipment across 18 miles of rough terrain, a month-and-a-half ordeal.
• July 25: The expedition reaches the headwaters of the Missouri in southwestern Montana.
• August 8: Sacagawea recognizes a natural formation from her childhood, Beaverhead Rock, indicating they are in the area where the Shoshone spend their summers.
• August 12: Lewis and three other men cross the Continental Divide at Lemhi Pass on the Montana-Idaho border. Meanwhile, the expedition's shipment arrives at the President's house in Washington.
• August 13: While Clark is on a scouting expedition, Lewis meets up with 60 warriors of the Shoshone nation. Once he establishes their peaceful intentions, he and his men are welcomed into the tribe's village.
• August 16: When the Shoshone become fearful of being led into a trap, Lewis lends his rifle to the Chief and his men follow suit. The gesture helps gain the Shoshone's trust.
• August 17: Sacagawea has a tearful reunion with her brother, now a Shoshone chief. Clark returns, and with Sacagawea's help, the Corps is able to negotiate for the horses needed to cross the Rockies.
• September 11: The Corps begins crossing the Bitterroot Mountains, the most dangerous leg of the entire journey. Over the next 11 days, the men struggle through deep snow. Starving, they resort to eating some of their colts.
• September 22: Emerging from the mountains, the expedition is taken in by the Nez Perce Indians. In the days ahead, everyone becomes sick from overeating the dried fish and boiled roots served by their hosts.
• September 26: The party travels down Idaho's Clearwater River to set up an encampment for building canoes. Work proceeds slowly as the men recover.
• October 7: The journey resumes.
• October 10: The expedition enters present-day Washington state at the Clearwater's confluence with the Snake River. They follow the Snake, the Columbia River's largest tributary.
• October 16: The Corps reaches the Columbia. A few miles to the south, the Columbia begins to follow the border between modern-day Oregon and Washington.
• October 18: Clark sights Mount Hood through the fog some 45 miles in the distance.
• October 22: The Corps descends Celilo Falls, the beginning of a treacherous 55-mile stretch of the Columbia.
• November 7: Clark writes in his journal, "Great joy in camp we are in View of the Ocian". His elation is premature. They have sighted the Columbia River's estuary and are still 20 miles from the Pacific.
• November 8: The waves in the estuary become too hazardous for the canoes, so they set up camp.
• November 10: The men attempt to make progress by hugging the shoreline, but the dangerous conditions again force them to shore.
• November 12: A violent thunderstorm strikes with hail, heavy rain and gale force winds. After burying all but one of their canoes under rocks to prevent them from being crushed by the waves and floating logs, they retreat by land to a cove up river. They are pinned down here for several days as the inclement weather continues.
• November 15: With a break in the weather, the estuary becomes navigable, enabling the Corps to reach the Pacific. The men land on a sandy beach that they name Station Camp. They spend the next 10 days here hunting, trading with the Chinook and Clatsop Indians and exploring the surrounding coastline.
• November 24: The Corps' members vote on a site for their winter encampment. Sacagawea and York, Clark's slave, participate in the vote. Following the recommendations of the local Indians, they pick a site on the Oregon side of the river where game is more plentiful.
• December 8: They begin building Fort Clatsop near modern-day Astoria, Oregon.
• December 30: The expedition's log fortress is completed, but the winter proves miserable as it rains during all but 12 days of their three-month stay.

  1806

• March 23: The Corps departs Fort Clatsop, eager to begin their journey home.
• April 18: The expedition reaches the Columbia's Great Falls. They need horses for re-crossing the Rockies, but the Indians demand steep prices so they buy only four.
• April 28: They leave Oregon, following the Columbia to the Snake River in southeastern Washington.
• May 3: After enduring a heavy snow storm, the Corps meets up with a familiar Nez Perce chief and 10 of his men.
• May 5: The expedition reaches present-day Idaho, where they pick up the Clearwater River.
• May 14: Having started their journey too early, the Corps must wait for the mountain snows to melt. The men camp for nearly a month in what is now the Nez Perce Reservation.
• June 10: They pull up camp and four days later reach the Bitterroot Mountains.
• June 24: The Corps starts to cross the Bitterroots. With the help of three Nez Perce guides, they cut 300 miles off the journey.
• June 29: The expedition enters western Montana through Lolo Pass.
• July 3: The Corps is divided in two to enable them to explore additional lands. Lewis leads one group down the Missouri, while Clark's takes a northern route following the Yellowstone River. Along the way, they break into smaller exploratory groups.
• July 25: Clark names a rock formation on the Yellowstone for Sacagawea's son, a site now known as Pompeys Pillar. Clark incribes his name and the date on the rock face, the only remaining physical evidence of the Corps' journey.
• July 26: Traveling on horseback, Lewis and his men encounter a small band of Blackfeet warriors. They spend the night together, but in the morning two Blackfeet braves are killed while trying to steal the group's guns and horses. Afraid of reprisals, the men ride for nearly 24 hours.
• August 2: Clark's group reaches the Missouri and enters present-day North Dakota.
• August 11: Lewis is accidentally shot in the buttocks by one of his men.
• August 12: The Corps reunites on the Missouri in western North Dakota near the mouth of Knife River.
• August 14: The expedition returns to a warm welcome by the Hidatsa and Mandan tribes.
• August 17: The men continue down the Missouri, leaving Charbonneau, Sacagawea and their son with the Mandans. Clark offers to raise the boy, who is now 19 months old. With the Missouri's current in their favor, they are able to cover over 70 miles a day.
• September 23: The Corps arrives in St. Louis, successfully concluding their 8,000-mile journey after two years, four months and 10 days.
• December 28: Lewis arrives in Washington, D.C. At the end of February, Jefferson nominates him as Governor of Upper Louisiana.

  1807

• January 15: Clark arrives in Washington, D.C. He is appointed Agent for Indian Affairs in the Louisiana Territory.

  Footnotes