The lowest elevation of Chicago, Illinois is 1,250 ft . The Chicago, Illinois city highest elevation is 91 m (299 ft) . Chicago, Illinois is at an elevation of 13 ft . This city is named after Confluence of Grand River and Gunnison River . 3,300/km 2  (8,600/sq mi) is the density of residents in  the urban region of Chicago, Illinois . Area: 572 km2 (221 sq mi) is the area of the city namedChicago, Illinois . The demonym of the city Chicago, Illinois is Cartagenero(s) (in Spanish) . The density of  people in  the metro region of Chicago, Illinois is 4,484/km 2  (11,610/sq mi) . Chicago, Illinois is the government of Ministry of Culture . The mayor of Chicago, Illinois is Solomon Mguni . The area of the urban region is 234.72 km 2  (90.63 sq mi) . 51°30′N 116°00′W﻿ / ﻿51.5°N 116.0°W﻿ / 51.5; -116.0 are the coordinates of the city. . The population of the metro region is Population (2015): 2,500,000 .  The city area code is 0211 . The city land area is 16.0 sq mi (41.4 sq km) . The water area of the city is 0.49 sq mi (1.27 km 2 ) . The city Chicago, Illinois province is Davao del Sur  (geographically only) . Chicago, Illinois is located in People's Republic of China . 850/km 2  (2,200/sq mi) is the density of residents in Chicago, Illinois . The postal code of the city is 130000
PS use 130000 to post mail in the city