Houston, the United States’ fourth most populated city, is featured in this photograph of the coastal plain of southeast Texas. Visible are dense, radial ground transportation patterns, including the western and northern sections of the outer Sam Houston Tollway (Beltway 8) that circumvents the city; runways for the two large commercial airports (north and south of downtown); the central business district showing lighter, reflective areas of commercial and industrial buildings and plants; and numerous residential subdivisions southwest, west, and northwest of downtown that appear lighter because of the removal of vegetative for construction. The highly reflective, industrialized Houston Ship Channel, part of Buffalo Bayou, radiates eastward from downtown. Apparent are part of Galveston Bay and its sediment pattern (lower right corner); brownish Lake Houston, a major source of potable water for the metropolitan area (right side); and the darker southern extent of the pine forests of east Texas (upper right corner).