On August 3, 1804, Lewis and Clark had their first council with native chiefs on a bluff overlooking the western bank of the Missouri River. For that reason the site was called "Council Bluffs". Present-day Council Bluffs uses that name, but it was established on the Iowa side of the river. William Clark later recommended the site as an excellent location for a fort, and when Congress decided to built a series of trading-posts in the Louisiana Territory that site was among the chosen locations. As it turned out, Fort Atkinson was the only one built and put into use.
After a few decades the fort fell into disuse. Fort Atkinson State Historical Park consists of a (huge) replica of the fort, and a visitors center where the staff is happy to answer questions. I watched the twenty-minute orientation video, and thought that it was pretty thorough. I really learned a lot about what motivated Congress to plan development of the fort system, the trials endured while constructing the fort, events that occurred during the years that it was in use, and how the fort later fell into disuse.
The replica is behind the visitors center, you can take a walk or drive down a very short paved path to see the fort.
The approach to the fort from the visitors center.
Along the inner walls are soldier's barracks and other rooms.
The shared cell.
The hospital. In front are displayed implements used by doctors at the fort, heaven please help us.
The powder magazine was situated at the center of the courtyard, as far from the walls as possible. This enhanced soldiers ability to defend it from attack, and protected residents of the fort by distancing their quarters from the magazine. It was the only structure with stone walls. This was required so that it would not be flammable, and so that in event of explosion the stone walls would direct the force of the explosion in an upward direction, away from the walls and its inhabitants.