Both the Mississippi River and the Missouri River have cut large valleys with wide flood plains.
Limestone and dolomite of the Mississippian epoch underlie the area, and parts of the city are karst in nature.
The earliest European settlements in the area were built in Illinois Country (also known as Upper Louisiana) during the 1690s and early 1700s at Cahokia, Kaskaskia, and Fort de Chartres.
Migrants from the eastern French villages founded Ste.
Coal, brick clay, and millerite ore were once mined in the city, and the predominant surface rock, the St. Louis County) is the River des Peres, practically the only river or stream within the city limits that is not entirely underground.
In 1904, it hosted the Louisiana Purchase Exposition and the 1904 Summer Olympics.Louis due to its earlier decision to become an independent city. Louis contains only 11% of its total metropolitan population, while the central city averages 24% of total metropolitan area population among the top 20 metro areas in the United States.During the 19th and 20th century, most major cities aggressively annexed surrounding areas as they grew out away from the central city, however St. Although small increases in population were seen in St.Louis, and gentrification has taken place in the Washington Avenue Historic District.(Not shown on simple maps of the city, the land at its airport is owned by the city, served by its fire department and others and is an exclave of St.Louis Cardinals, one of the most successful Major League Baseball clubs, the St. Louis was a center of Native American Mississippian culture, which built numerous temple and residential earthwork mounds on both sides of the Mississippi River.