Following the Missouri River north, they began their journey with a keelboat. It measured fifty-five ft. long, eight ft. wide in the middle and four ft. wide at each end. It had a cabin at one end and a mast in case they encountered a favorable wind. They also had two pirogues, which are dugout canoes, and two horses, which would be used mostly by the hunters. Traveling against the current of the river, their progress was slow because of shallow waters. They paddled the boat when possible. However, sometimes they would have to cordelle, which meant the men had to get out and pull the boat with ropes either from the shore or wadding in the water. At other times the men had to push the boat along with long poles.
Two days after beginning their journey the Corps of Discovery had their first of many troubles with the men. When some of the men had gone ashore without leave to a party, one of them stayed out all night and was rewarded for his actions with fifty lashes. In June, three men stole some whiskey and received one hundred lashes as punishment. One month later a guard fell asleep while on duty. This neglect of his duty endangered the whole crew. His punishment was four hundred lashes.
On top of the disciplinary problems, the Corps of Discovery would have to deal with health problems. There were bugs which at times seemed to plague them. The bugs gave the men anything from dysentery to skin infections. On August nineteenth, the first and only man to die on the trip passed away for unknown reasons.
The explorers made contact with many Indian tribes as the passed through the country from St. Louis to what is now North Dakota. The first ones they encountered were the Oto and Missouri Indians. Lewis and Clark gave a speech and then presented them with peace medals. The same was done when the group met the Yankton Sioux Indians. The next Indians they met would be the only unfriendly tribe of the entire expedition.