Indianapolis is located in the East North Central region of the Midwestern United States, about 14 miles (23 km) south-southeast of Indiana's geographic center.[82] According to the U.S. Census Bureau, the Indianapolis (balance) encompasses a total area of 367.9 square miles (953 km2), of which 361.6 square miles (937 km2) is land and 6.3 square miles (16 km2) is water.[4] It is the 18th largest city by land area in the U.S.
As a consolidated city-county, the city's municipal boundaries are coterminous with Marion County, except the autonomous and semi-autonomous municipalities outlined in Unigov.[43][83] Nine civil townships form the broadest geographic divisions within the city and county.[84] The consolidated city-county borders the adjacent counties of Boone to the northwest; Hamilton to the north; Hancock to the east; Shelby to the southeast; Johnson to the south; Morgan to the southwest; and Hendricks to the west.[85]
Indianapolis is located within a physiographic province known as the Tipton Till Plain, a flat, gently rolling terrain underlain by glacial deposits known as till. The lowest point in the city is about 650 feet (198 m) above mean sea level, with the highest natural elevation at about 900 feet (274 m) above sea level.[86] Few hills or short ridges, known as kames, rise about 100 feet (30 m) to 130 feet (40 m) above the surrounding terrain. The city lies just north of the Indiana Uplands, a region characterized by rolling hills and high limestone content.
Indianapolis is located in the West Fork White River drainage basin, part of the larger Mississippi River watershed[87] via the Wabash and Ohio rivers.[85] The White River is fed by some 35 tributaries, including Fall Creek and Pogue's Run, as it flows 31 miles (50 km) north to south through Indianapolis.[88] The city's largest water bodies are artificial quarry lakes or reservoirs.