Museum of Westward Expansion is within the Jefferson National Expansion Memorial, on Market St. at Riverfront (beneath The Gateway Arch). An extensive collection of artifacts is displayed in conjunction with exhibits relating to the Lewis and Clark expedition and the social and cultural history of territories west of the Mississippi River.
Note: The museum is closed for a major renovation and is scheduled to reopen in summer 2018. Phone ahead for updated information. Tickets for The Gateway Arch can be purchased at The Old Courthouse.