|Wisconsin is the 20th most populous state in the United States. According to an estimation in 2008, the state had a population of 5.6 million residents. Moreover, the state ranks 23rd in terms of geographical area with a total area of 65,498 square miles. It is 310 miles long and 260 miles wide. The population density is 98.8 per square mile while median income is $47,220. Located in the north central part of the US, the state borders Michigan to the north, Illinois to the south, and Iowa and Minnesota to the west. The state is also bordered by the Montreal River and Lake Superior to the north and Lake Michigan to the east. Within the state's boundaries are Mississippi River, St. Croix River and Menominee River. Wisconsin is divided into five geographical regions, namely Lake Superior lowland, the Northern Highland, the Central Plain, the Eastern Ridges and Lowlands region, and the Western Upland. Forest covers about 46 percent of Wisconsin's land area. Milwaukee is the largest city and Madison is the capital of the state.