The Missouri State Museum occupies the ground floor of the State Capitol building and is one of those genuinely good free state museums that most visitors walk past on the way to the rotunda. The exhibits cover Missouri's natural history, Native American cultures, and the state's role in American expansion westward — the Gateway to the West narrative is given serious historical treatment rather than tourist-brochure treatment.
The Missouri room on the building's ground floor is particularly strong, with a large diorama of Missouri landscapes and a collection of trade goods and artifacts from the fur trade era. It takes about an hour to do it properly.