This museum occupies the fort's old cavalry stables, with a recreated pioneer village outside. The main exhibit hall contains displays on the Lewis and Clark expedition, local agriculture and military history, and the four large stable buildings hold collections of farm implements, a jail cell and a plastic replica of a 33-mule team used for harvesting wheat in the 1920s.
The museum by itself lacks a certain narrative zing, so if you're really keen to learn about the area, consider requesting a guided tour through the displays.