The capital city of Arkansas, Little Rock, occupies a position near the geographic center of the state. It sits between the eroded remnants of the Ouachita Mountains to the west, the Mississippi River Alluvial Plain to the east, and the West Gulf Coastal Plain to the south. This photograph, taken by an astronaut on the International Space Station, highlights the Little Rock metropolitan area and surrounding region. Urban and suburban areas appear light to dark gray, while large facilities and buildings (commercial/industrial, public arenas, etc.) stand out due to expansive light-colored roofs. The Arkansas River separates Little Rock on the south bank from North Little Rock on the north bank. Frequent changes in the position of the river channel through geologic time are recorded as numerous current and former oxbow lakes visible within extensive agricultural fields. Oxbow lakes are formed on river floodplains when wide meander bends are "pinched off" due to the river cutting a shorter channel across the bend. The process forms a lake, which typically becomes filled in with sediment over time; vegetation outlines a distinctive curved pattern visible from above.