1 March 10 Lewis and Clark go to Saint Louis, Missouri, where France turns Louisiana over to the United States.

2 May 14 The explorers leave their camp (Camp Wood) near Saint Louis. They row and pole their boats up the Missouri River. Sometimes the men wade and pull the boats with ropes.

3 May 25 The explorers pass La Charette, Missouri. This village of seven homes is the last white settlement on the river.

4 August 3 Lewis and Clark meet with Oto and Missouri Indians at Council Bluff (near present-day Omaha, Nebraska). This meeting is the first official meeting between people from the United States and members of a western Indian tribe.

5 August 20 Sergeant Charles Floyd dies from a burst appendix near present-day Sioux City, Iowa. He was the only member of the Corps of Discovery to die on the journey. The men had to pick another person to act as sergeant. A day later, near Elk Point, South Dakota, they held the first election in this part of the country.

6 August 21- October 14 The corps travels through South Dakota (covered in student section, Lessons 2 and 3).

7 October 24 The expedition reaches the Mandan Indian village. They build a fort to stay in during the winter.


7 February 11 Sacagawea gives birth to her son, Jean Baptiste. The men later call him "Pomp" for the proud way he dances around the camp.

7 April 7 Some corps members take the big boat back down the river. It is full of samples of plants and minerals for scientists to study. The rest of the Corps of Discovery heads west to the Pacific Ocean. Sacagawea and her son go with them.

8 May 31 Lewis and Clark pass into a beautiful section of the Missouri River Breaks in Montana. Today, these sandstone cliffs are almost unchanged.

9 June 2 The group reaches a fork in the river. How will they decide which branch of the river to follow? The leaders know they must cross the mountains before long. They decide to follow the south fork because the water is clear. Water coming from the mountains should be clear. They name the north fork the Marias River. Indians told the explorers to look for a great waterfall on the Missouri River. If they find that waterfall, they will be on the right fork of the river.

10 June 13 The corps reaches the Great Falls. It takes the men almost a month to carry their supplies around the falls. The ground is rough and covered with cactus.

11 July 30 The corps faces another choice. This time, there are three forks. They decide to follow the fork they call the Jefferson. They are right again.

12 August 12 Lewis reaches the source of the Missouri River. The explorers have answered one question. The Missouri River does not connect with the Pacific Ocean. There may be another river nearby that does. On the same day, Lewis reaches the Continental Divide. The Continental Divide is the point where rivers to the east run to the Mississippi River and rivers to the west run to the Pacific Ocean. From the divide at Lemhi Pass, Lewis sees huge mountains ahead. He is disappointed. He had hoped to see a river flowing toward the Pacific Ocean.

13 August 17 In present-day Idaho, the expedition meets the Shoshone Indians. Sacagawea’s brother is chief. The Indians sell the explorers horses to use in crossing the mountains. A member of the tribe stays with the corps as a guide.

14 September 11 The corps starts climbing the Rocky Mountains. They get lost, and it takes them eleven days to get across. To stay alive, they eat a few of their horses and candles made of animal fat.

15 Late September & Early October The corps staggers out of the mountains. The Nez Perce Indians give them new supplies and teach them how to hollow out logs with fire to make new canoes. The corps then speeds down the Snake and Columbia rivers.

16 October 18 Clark sees Mount Hood ahead and knows they are close to the Pacific Ocean. A British sea captain had named this mountain in 1792, and it was on maps. European and Asian people had come by sea to trade along the coast of the Pacific Northwest. Lewis and Clark were the first to come overland from the United States.

17 November 7 Clark thinks he sees the ocean and writes in his journal: "Ocian in view! O! the joy." Actually, they are still twenty miles from the sea. Three weeks later, a small group reaches the Pacific Ocean.

18 November 24 The corps votes on where to stay for the winter. For the first time, a woman (Sacagawea) and a black man (York) get to vote in an American election. They build Fort Clatsop and name it for their neighbors, the Clatsop Indians.


18 March 23 The corps starts for home.

19 July 3 Lewis and Clark split the expedition into two groups. Clark’s group explores the Yellowstone River. Lewis and the others explore the Marias River and northern parts of the Louisiana Purchase.

20 July 25 Clark names a big rock "Pompy’s Tower" after Sacagawea’s son. Clark carves his name and the date into it. This rock is known today as Pompeys Pillar.  It is in present-day Montana, and Clark’s name is still there.

21 July 26-27 Lewis’s group meets eight Blackfeet warriors. They camp together. In the morning, the Indians try to steal the explorers’ horses and guns. Two Blackfeet men are killed in the only fight of the whole expedition.

22 August 12 The two groups of the Corps of Discovery meet up again downstream from the mouth of the Yellowstone River.

23 August 14 At the Mandan village, the explorers say good-bye to Sacagawea and her family.

24 September 23 The corps arrives in Saint Louis. Many people thought they had died in the wilderness. They are treated like heroes.