The Lewis & Clark Corps of Discovery left Wood River Illinois and crossed the Mississippi River into Missouri on May 14, 1804.
They spent their first night of their westward trip camped on an island in the Missouri River across from Cold Water Creek.
They traveled up the Missouri River to its source and onward to the Pacific Ocean. The Corps had a surprise waiting for them on their return trip on September 22, 1806.
Along the Missouri River, next to Cold Water Creek, across from the spot where they had camped two years earlier, was a United States Army fort.
The fort, officially named Cantonment Belle Fontaine, had been built in 1805 about four miles up from the confluence of the Missouri and Mississippi rivers.

This was the first United States fort west of the Mississippi River after the Louisiana Purchase and was occupied by the First Infantry under the command of Lieutenant Colonel Jacob Kingsbury.
The fort also served as a trading post or Indian Factory for the local Indian tribes until 1808.
This was the only established military presence in the new Louisiana Territory and was instrumental as a starting and stopping point for many notable explorers and expeditions.
Lewis and Clark and their men spent the night at this new fort before heading down the Mississippi River to St. Louis.
There had been a fort built by the Spanish near this location in 1767 but it had long disappeared. Colonel Kingsbury chose this site because of its strategic location and the presence of a large spring that produced enough pure water to supply one thousand men daily.

The original fort was built at the bottom of a bluff next to the river and the spring. But constant flooding, mosquitoes, and the eventual deterioration of the buildings caused this location to be problematic.
General Daniel Bissell took command of Fort Belle Fontaine in 1809 and found the cantonment in a terrible state of disrepair and the men plagued with illness.
The Missouri River was shifting on the flood plain and also threatening the fort.