The bright white area in this ASAR image is the city of St. Louis, Missouri, USA. According to the United States Census Bureau, St. Louis has a total area of 66.2 square miles (171.3 km²), of which 61.9 square miles (160.4 km²) is land and 4.2 square miles (11.0 km² or 6.39%) is water. The city is built primarily on bluffs and terraces that rise 100–200 feet above the western banks of the Mississippi River, in the Midwestern United States just south of the Missouri-Mississippi confluence. Much of the area is a fertile and gently rolling prairie that features low hills and broad, shallow valleys. Both the Mississippi River and the Missouri River have cut large valleys with wide flood plains.
The Missouri River forms the northern border of St. Louis County, exclusive of a few areas where the river has changed its course. The Meramec River forms most of its southern border. To the east is the City and the Mississippi River. Near the southern boundary of the City of St. Louis (separating it from St. Louis County) is the River des Peres, virtually the only river or stream within the city limits that is not entirely underground. Most of River des Peres was confined to a channel or put underground in the 1920s and early 1930s.